Cannot upgrade PHP

[Tuffiglig]

Hey Chris.
This is a guide in german, howto update php from 7.4 to 8.0.
Maybe it will help you to find the missing piece.

Nextcloud 23 mit PHP 8.0 nachrüsten und optimieren - Carsten Rieger IT-Services

edit:
maybe this post is also helpfull:

Change PHP version from 7.2.33 to 7.4

Hi @ll ! I want to update my php version from 7.2 to 7.4 on a LEMP based system (Ubuntu 18.04, NC 18.0.7, mysql 10.1.44). I already installed the packages as mentioned in the second chapter of this guide : https://www.c-rieger.de/nextcloud-installationsanleitung/ works fine, [grafik] but i still have to change the php version in nginx… How can i do that? [grafik] In apache it was something like: a2dismod php7.2 a2enmod php7.4 Thx for your help!