When I click "enable secure and erase" in Find My device it says "request sent", but nothing happens

I'm trying to enable remote locking and wiping for a phone. When I go to https://www.google.com/android/find and click on “enable secure and erase” then it says "request sent", but I see nothing on the phone, no notification. The strange thing is I can ring the phone via the web interface, so it reaches the phone, but I cannot enable lock and wipe, because I get no notification on the phone after "request sent". Why can this be?