Accessing corteza via SSH as user other than root

Not sure if I am posting this in the correct section.

I have taken steps to secure my server.
I have added a new user and revoked access to Root.

However, Now when I want to take a backup “dump” of the corteza database, It tells me that I do not have permissions.
Similarly when I try to do anything in the corteza folder over FTP, I get a smililar message.

My new user has been allocated root privelages on the server. Is there something different that I need to do in order to have full access to corteza?

I have ran su usermod -aG docker ${USER} which now allows me to view running containers etc but cannot take dumps, put containers up, bring down etc.

Any help would be appreciated.

How do you do the database dump for the backup?
Can you share your command?

Does following these instructions here help in anyway?

@darh sorry, was my mistake, I hadnt changed the folder ownership from root to $USER
Working now