Failing to complete installation

Hi , I’m facing this error when i install nextcloud on ubuntu 21. may you please assist.

ubuntu@sea-clutter-server:~$ sudo a2ensite rewrite headers dir mime env setenvif ssl
ERROR: Site rewrite does not exist!
ERROR: Site headers does not exist!
ERROR: Site dir does not exist!
ERROR: Site mime does not exist!
ERROR: Site env does not exist!
ERROR: Site setenvif does not exist!
ERROR: Site ssl does not exist!
ubuntu@sea-clutter-server:~$

I think correct is:
sudo a2enmod rewrite headers dir mime env setenvif ssl

It is not a good idea to install Nextcloud on a Ubuntu beta version (21.04, 21.10).
Use LTS realeases e.g. Ubuntu 20.04 LTS or Ubuntu 22.04 LTS.
Read Ubuntu release cycle | Ubuntu

Nice Nextcloud installation guide (Ubuntu 22.04 LTS with apache2)
How to Install Nextcloud with Apache and Let's Encrypt SSL on Ubuntu 22.04 LTS

And for Debian (Debian 11 with apache2)
https://www.howtoforge.com/how-to-install-nextcloud-on-debian-11