Internal server error after installing using tarball and occ

EDIT: It works now!

Nextcloud version: 20
Operating system and version: Arch Linux
Apache or nginx version: Apache/2.4.46 (Unix)
PHP version: PHP 7.4.12
Database: MariaDB (MySQL)

I installed Nextcloud by extracting the tarball and using occ to install it. I succsesfully installed it, but it gives me this error when I point my web browser to it:
Internal Server Error

The server encountered an internal error and was unable to complete your request.

Please contact the server administrator if this error reappears multiple times, please      include the technical details below in your report.
More details can be found in the server log.

How to fix this?

If it works, it would be nice to share the solution as well :wink: