diff --git a/packages/nextjs/pages/example-zk/BirthDateSignature.tsx b/packages/nextjs/pages/example-zk/BirthDateSignature.tsx
index e28f139..1442f92 100644
--- a/packages/nextjs/pages/example-zk/BirthDateSignature.tsx
+++ b/packages/nextjs/pages/example-zk/BirthDateSignature.tsx
@@ -38,12 +38,20 @@ export const signBirthYear = async (form: TForm) => {
 
 export const BirthDateSignature = ({ aliceDefaultAge }: { aliceDefaultAge: number }) => {
   const [form, setForm] = useState<TForm>(() => getInitialFormState(aliceDefaultAge));
+  const ethereumAddress = useBirthYearProofsStore(state => state.ethereumAddress);
+  const setEthereumAddress = useBirthYearProofsStore(state => state.setEthereumAddress);
+  const birthYear = useBirthYearProofsStore(state => state.birthYear);
+  const setBirthYear = useBirthYearProofsStore(state => state.setBirthYear);
   const setSignedBirthYear = useBirthYearProofsStore(state => state.setSignedBirthYear);
   const setSignerPublicKey = useBirthYearProofsStore(state => state.setSignerPublicKey);
 
   const handleSubmission = async () => {
     try {
-      const { signedMessage, signerPublicKey } = await signBirthYear(form);
+      const { signedMessage, signerPublicKey } = await signBirthYear({
+        ...form,
+        personEthereumAddress: ethereumAddress,
+        birthYear,
+      });
       setSignedBirthYear(signedMessage);
       setSignerPublicKey(signerPublicKey);
       notification.success("Successfully signed birth year");
@@ -84,10 +92,10 @@ export const BirthDateSignature = ({ aliceDefaultAge }: { aliceDefaultAge: numbe
               <span className="label-text">Enter your Ethereum address</span>
             </label>
             <AddressInput
-              value={form.personEthereumAddress}
+              value={ethereumAddress}
               name="personEthereumAddress"
               placeholder="Ethereum address"
-              onChange={(val: string) => setForm({ ...form, personEthereumAddress: val })}
+              onChange={(value: string) => setEthereumAddress(value)}
             />
           </div>
           <div className="form-control">
@@ -98,8 +106,8 @@ export const BirthDateSignature = ({ aliceDefaultAge }: { aliceDefaultAge: numbe
               type="number"
               placeholder="Birth year"
               className="input input-bordered"
-              value={form.birthYear}
-              onChange={e => setForm({ ...form, birthYear: e.target.value as unknown as number })}
+              value={birthYear}
+              onChange={e => setBirthYear(e.target.value)}
             />
           </div>
           <div className="form-control">
diff --git a/packages/nextjs/pages/example-zk/GenerateProof.tsx b/packages/nextjs/pages/example-zk/GenerateProof.tsx
index 047418c..ac91287 100644
--- a/packages/nextjs/pages/example-zk/GenerateProof.tsx
+++ b/packages/nextjs/pages/example-zk/GenerateProof.tsx
@@ -61,6 +61,10 @@ export const parseForm = (form: TForm) => {
 };
 
 export const GenerateProof = ({ requiredBirthYear }: { requiredBirthYear: number }) => {
+  const ethereumAddress = useBirthYearProofsStore(state => state.ethereumAddress);
+  const setEthereumAddress = useBirthYearProofsStore(state => state.setEthereumAddress);
+  const birthYear = useBirthYearProofsStore(state => state.birthYear);
+  const setBirthYear = useBirthYearProofsStore(state => state.setBirthYear);
   const setProof = useBirthYearProofsStore(state => state.setProof);
   const signedBirthYear = useBirthYearProofsStore(state => state.signedBirthYear);
   const signerPublicKey = useBirthYearProofsStore(state => state.signerPublicKey);
@@ -73,7 +77,7 @@ export const GenerateProof = ({ requiredBirthYear }: { requiredBirthYear: number
     setIsProofRunning(true);
     const notifcationId = notification.loading("Generating proof...");
     try {
-      const parsedForm = parseForm(form);
+      const parsedForm = parseForm({ ...form, personEthereumAddress: ethereumAddress, birthYear });
       const { proof } = await generateProof("LessThanSignedAge", parsedForm as ParsedArgs);
       setProof(`0x${proof}`);
       notification.success("Proof generated");
@@ -120,8 +124,8 @@ export const GenerateProof = ({ requiredBirthYear }: { requiredBirthYear: number
                 type="number"
                 placeholder="Signed birth year"
                 className="input input-bordered"
-                value={form.birthYear}
-                onChange={e => setForm({ ...form, birthYear: e.target.value as unknown as number })}
+                value={birthYear}
+                onChange={e => setBirthYear(e.target.value)}
               />
             </div>
             <div className="form-control">
@@ -133,7 +137,7 @@ export const GenerateProof = ({ requiredBirthYear }: { requiredBirthYear: number
                 placeholder="Required birth year"
                 className="input input-bordered"
                 value={form.requiredBirthYear}
-                onChange={e => setForm({ ...form, requiredBirthYear: e.target.value as unknown as number })}
+                onChange={e => setForm({ ...form, requiredBirthYear: Number(e.target.value) })}
               />
             </div>
           </div>
@@ -168,10 +172,10 @@ export const GenerateProof = ({ requiredBirthYear }: { requiredBirthYear: number
               <span className="label-text">*Ethereum address signature</span>
             </label>
             <AddressInput
-              value={form.personEthereumAddress}
+              value={ethereumAddress}
               name="personEthereumAddress"
               placeholder="Ethereum address in signature"
-              onChange={(val: string) => setForm({ ...form, personEthereumAddress: val })}
+              onChange={(value: string) => setEthereumAddress(value)}
             />
           </div>
           <div className="form-control mt-6">
diff --git a/packages/nextjs/pages/example-zk/ZkSteps.tsx b/packages/nextjs/pages/example-zk/ZkSteps.tsx
index 309635b..c5297e7 100644
--- a/packages/nextjs/pages/example-zk/ZkSteps.tsx
+++ b/packages/nextjs/pages/example-zk/ZkSteps.tsx
@@ -41,13 +41,15 @@ const ZkSteps: NextPage = () => {
             >
               Previous
             </button>
-            <button
-              className="join-item btn btn-outline"
-              onClick={() => setCurrentStep(currentStep => currentStep + 1)}
-              disabled={currentStep === LAST_STEP}
-            >
-              Next
-            </button>
+            {currentStep !== LAST_STEP && (
+              <button
+                className="join-item btn btn-outline"
+                onClick={() => setCurrentStep(currentStep => currentStep + 1)}
+                disabled={currentStep === LAST_STEP}
+              >
+                Next
+              </button>
+            )}
           </>
         )}
       </div>
diff --git a/packages/nextjs/services/store/birth-year-proofs.ts b/packages/nextjs/services/store/birth-year-proofs.ts
index 1c9fd88..369cc0e 100644
--- a/packages/nextjs/services/store/birth-year-proofs.ts
+++ b/packages/nextjs/services/store/birth-year-proofs.ts
@@ -2,18 +2,26 @@ import { create } from "zustand";
 import { HexString } from "~~/hooks/noir/useProofGenerator";
 
 type BirthYearProofs = {
+  ethereumAddress: string;
+  birthYear: number;
   signedBirthYear: string;
   signerPublicKey: string;
   proof: HexString;
+  setEthereumAddress: (input: string) => void;
+  setBirthYear: (input: string) => void;
   setSignedBirthYear: (input: string) => void;
   setSignerPublicKey: (input: string) => void;
   setProof: (input: HexString) => void;
 };
 
 export const useBirthYearProofsStore = create<BirthYearProofs>(set => ({
+  ethereumAddress: "",
+  birthYear: 2014,
   signedBirthYear: "",
   signerPublicKey: "",
   proof: "0x",
+  setEthereumAddress: (input: string) => set({ ethereumAddress: input }),
+  setBirthYear: (input: string) => set({ birthYear: Number(input) }),
   setSignedBirthYear: (input: string) => set({ signedBirthYear: input }),
   setSignerPublicKey: (input: string) => set({ signerPublicKey: input }),
   setProof: (input: HexString) => set({ proof: input }),