AppPresser apps come with a registration form that allows users to sign up quickly to get a login for the app.
When they sign up, the user is added to your site as a Subscriber with a meta value of app_unverified = true. They are sent an email with a verification code, which they can enter into the app. This removes the app_unverified meta value and allows them to login to the app.
To allow users to register (free) in your app, visit Login Settings tab and check "Allow users to register" and enter the URL as prompted.
You must have a WordPress URL set in the login settings.
The registration form will only show in the app login modal, so you can add the login button to the side menu as shown above, or add a menu item that opens it.
Custom Registration Form
If you want a custom registration form, add the url under WordPress Registration URL. Note that this must be https, on the front-end (can't be register.php or any admin page), and it bypasses all the functionality mentioned above.
In App Purchase Form for Registration
If you'd like to send app users to an in app purchase form when they click Sign Up, first create the custom page under Custom Pages => Add New => Custom HTML. Add the in app purchase form there, as described in this article.
Save the page and add it to your menu.
Next, re-open the page under Custom Pages => [your page name], and click CSS & Code Help to view the page slug.
Copy the page slug, then leave the app customizer, and go back to your app dashboard. Click the "Login settings" tab, and click "Use custom registration page" and then add your page slug and save.
Now users will be redirected to your custom in app purchase page when they click "sign up" in the login modal.