Problem to install Collabora Online - Built-in CODE Server

I installed the NextCloud plugin on my Plesk server and now I’m trying to setup the email and collabora features.

So, far I haven’t been able to install the " Collabora Online - Built-in CODE Server" App.

Here it says that I can run one command to install it:

But where can I run that command?. Since I’m running NextCloud as Plugin of Plesk.

If I SSH to my plesk server and just copy/paste the line I got this:

`[root@panel nextcloud]#

[root@panel nextcloud]# sudo -u Adm***** php -d memory_limit=512M ./occ app:install richdocumentscode
sudo: unknown user: Adm*****
sudo: unable to initialize policy plugin

[root@panel nextcloud]#`

How can I install this App?