If MBS is installed then it exposes a small API accessible from globalThis.mbs (i.e. an mbs object in the global namespace). In order to safely use the API it is strongly recommended to place mbs access behind an undefined guard in case it isn't loaded. Note that checks against API_VERSION.major, while not strictly required, are recommended.
if (typeof mbs !== "undefined" && mbs.API_VERSION.major === 1) {
console.log(mbs.MBS_VERSION);
}See the mbs.d.ts file (which can be copy/pasted into the project of your choosing) for a full overview and documentation of the API.