New to Kopia - want to make a repository server

Hi All
I have a few tasks I want to complete with Kopia 0.21.1
Backup of all workstations
Backup of NAS

I’ve made a POC install on one workstation, with a GUI directly to the NAS filesystem, and it works nicely. Still has to filter out quite a bit, as I get a lot of errors from eg. $RECYCLE.BIN

Now I want to make the repository server for a preparation of a NAS backup (it’s a unify nas, so the native software lacks dedup and compression).

I’ve gotten the server installed on my Proxmox in a linux container.
I’ve gotten a ‘unit’ made for systemctl, and I can start it from there.
I’ve created a repository on an S3 storage.
I can connect to the repo server with a kopia client.

What I can’t get to work properly is to connect to the Web UI on the repo server.
I’ve found different suggestions online and through chatgpt, but none of them are good.
The most success I’ve had was to add --server-control-username kopia (control as suggested in the docs doesn’t work) and then give the password on the commandline for the unit. But I really don’t like to have a password in plain sight in the unit for systemctl

Even with that set, I have to log in twice to the webinterface, which is really weird.

So what do I do, how do I get a proper weblogin created and set up?