Continuing the discussion from How to Install the Latest Version of Rainloop?:
In order to install RainLoop Webmail, you need to have access to an administrator account for your Nextcloud server. Once you do, log in to Nextcloud and follow these steps.....
How would I access the administrator account on my MIAB/Nextcloud server?
See if this one helps: https://discourse.mailinabox.email/t/admin-login-owncloud/101/2?u=just4t
I think you are trying to tell me to enter
into the command line?