Where do i get an auth key
I believe our server set up document covers obtaining and using auth keys. Please keep in mind that you only need an auth key if you want your server to be fully public and show up on the public server listing when people browse BeamMP. If you are setting up a server just for you and your friends to direct connect to an auth key is not required.
You can also join the Patreon at https://www.patreon.com/BeamMP and choose a backer level to get keys as a thank you for supporting the project 