How to make User to use only API not the erp

Is there any way how to restrict specific users to use the ERP? I am building a separate web app for specific users. I want them to get data and show in this web app, but these logged in users (logged in via OAuth via ERPNext), must not be allowed to use the ERPNext.
Is there any way?

Any idea guys?

Try these workarounds,

Set a default page which is shown to user after login.

Restrict desk view for some Roles


refer following and change of your custom app to have desired effect.

Let the user see the frappeā€™s webview, It has account, profile and third party apps management pages which may be useful for user