As you know Nokia 7 plus is listed at the android beta site. But to get the OTA you need to login and authorise your device.....
What do you mean by you can not log in? I assume you registered >here< for the Android P program, right? Do you get an error message ?
P.S. OTA is not available for the Android P program yet, you have to flash the phone manually.
I can login with Firefox, so Opera is not the only solution
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