Cannot launch MM desktop Ubuntu 20.04

sudo mattermost &
[3] 10960
(base) v@v:~$ {"timestamp":"2022-09-28 14:18:40.556 +03:00","level":"info","msg":"Server is initializing...","caller":"app/server.go:269","go_version":"go1.18.1"}
{"timestamp":"2022-09-28 14:18:40.557 +03:00","level":"info","msg":"Pinging SQL","caller":"sqlstore/store.go:228","database":"master"}
{"timestamp":"2022-09-28 14:18:40.562 +03:00","level":"error","msg":"Failed to ping DB","caller":"sqlstore/store.go:238","error":"pq: password authentication failed for user \"mmuser\"","retrying in seconds":10}

?

This might be related to MM on Ubuntu 20.04; sudo? - not sure if we should work on both issues at the same time.
Anyways the error message here is that your provided database connection details in your config.json file are wrong (the system cannot connect with the details there to your database).
What installation instructions did you follow?

In the beginning I wrongly followed the server installation instructions - Deploy Mattermost — Mattermost documentation

Then the desktop installation instructions - Deploy Mattermost — Mattermost documentation

Is this issue still relevant here now that we fixed the problem in the other topic?

The issue was fixed in MM on Ubuntu 20.04; sudo? - #12 by agriesser