I have created an a Public APP and am trying to change the APP to be a payment APP. Have tried to go to the App settings and clicking Extensions as per the documentation provided by Shopify by following the below steps
To configure your app extension:
From your Partner Dashboard, clickApps.
Click the name of the app that you want to change.
Enter your extension name and select save.
However in the extensions, I do not have Payments Visible.