What is it used for ?

It is running all the cronjobs needed for deemixrr to work properly.

How do I get there ?

Look at your docker-compose.yaml and find the settings prefixed with Hangfire__.

There is a variable for the path called Hangfire__DashboardPath. Use the value from there as a path for your domain. Since the default value is /autoloaderjobs go to http(s)://sub.domain.com/autoloaderjobs and enter the username from the Hangfire__Username variable and the password from the Hangfire__Password variable.

For cloudb0x users, use the password that is used for radarr/sonarr.