How to fix this?
I reinstalled the game to the regular version instead of the beta test and now I can’t log in, how can I fix it?

Solution
I understand. If you allowed the app to read files but it still didn't work, looks like your only option is to delete the game along with the files you saved then reinstall it.
If that still doesn't work, you can submit a bug report from https://pubgmobile.live/support > Bug.
If that still doesn't work, you can submit a bug report from https://pubgmobile.live/support > Bug.