a cool feature of the free and open source privacy-respecting dialer i downloaded at the same time as the contacts app is that if my phone rings while it is locked i cannot answer it
it never asked for the permission to show on the lock screen, so i have to unlock my phone to answer, except pressing the unlock button means "ignore". once i do unlock there's nothing, no notification, nothing in the dialer app, it's silently ringing in the background and 10 seconds later it will say "missed call"