Link not working in my Flutter App.

[rossnelson111]

I believe this repo will help me immensely with building my app but I am having trouble with it at the moment.

I have implemented the code found in the example folder but I am getting a 'create' issue, as shown by the screenshot attached.
https://github.com/jorgefspereira/plaid_flutter/blob/master/example/lib/main.dart

I am first generating a link token from the API endpoint:
https://sandbox.plaid.com/link/token/create

I have also tried a production link token.
Then I am passing the link token to the example code taken from GitHub as mentioned previously. I then click 'Create Link Token Configuration' and then 'Open' and I get the error shown in the screenshot.

Do you have any idea what the problem is?
If this is an easy fix then please let me know, if it's a bit more complicated I am happy to pay for a consulting hour or two in order to figure out the issue.