Tried this. The output I get is:
admin@myserver:~$ sudo murmurd -supw MY_PASSWORD
<W>2021-12-12 19:52:58.005 SSL: OpenSSL version is 'OpenSSL 1.1.1d 10 Sep 2019'
<W>2021-12-12 19:52:58.005 Initializing settings from /etc/mumble-server.ini (basepath /etc)
<W>2021-12-12 19:52:58.304 MetaParams: TLS cipher preference is "TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA:AES256-SHA:AES128-SHA"
<C>2021-12-12 19:52:58.305 Successfully switched to uid 123
<W>2021-12-12 19:52:58.339 ServerDB: Opened SQLite database /var/lib/mumble-server/mumble-server.sqlite
<W>2021-12-12 19:52:58.339 ServerDB: Using SQLite's default rollback journal.
<F>2021-12-12 19:52:58.369 Superuser password set on server 1
But when I try to login to the server I get:
