I get a 500 error when going to /phpmyadmin in my browser after LAMP install

I’m testing phpmyadmin after installing lamp-server on Ubuntu 20.04 LTS.

First I installed lamp-server, then phpmyadmin

I made sure to select apache2 during the installation and I used dbconfig-common

(I didn’t need to link phpmyadmin to apache2 thanks to dbconfig-common)

Finally, I restarted apache2

Then I went to browser, typed my server’s IP address and I got the index.html page. But when I try to go /phpmyadmin I get a 500 error

P.S. I have also tried some of the suggestions from the best answer on this thread How to solve the phpmyadmin not found issue after upgrading php and apache?, namely, adding a symlink to phpmyadmin on /var/www/html/