How to fix phpmyadmin white screen after changing php version?

Question

linux

Installed:
ubuntu 20.04
nginx 1.18
mysql 8.0
php 8.1
phpmyadmin
Set up localhost/phpmyadmin and everything worked
Then I changed the php version to 8.0, when localhost/phpmyadmin enters a white screen, there is no authorization window.
Recently I started to understand linux, I don’t even know where to dig, I ask you for help)
I do everything on virtualbox

Answer 1

call to undefined function
most likely some php extension is missing

Answer 2

Install an additional version of php 7.4 (so that nginx + fpm is easy to do)
connect it to nginx for phpmyadmin, I don’t see 8 php subversions on the site. Better
yet, install a web panel so that there are a million of them and they are installed in 1 click