Custom tabs allow Android apps to open websites in the app itself. If you disable it, when you tap on a link the page will open with your default browser instead of inside the app.
Basically an embedded browser instead of opening in a new app window.
I posted a link for this. The custom tabs documentation is at: https://developer.chrome.com/docs/android/custom-tabs/
https://sh.itjust.works/post/354507
Custom tabs allow Android apps to open websites in the app itself. If you disable it, when you tap on a link the page will open with your default browser instead of inside the app.
Basically an embedded browser instead of opening in a new app window.