I was trying to create a server with my friend so me and him could do multiplayer private server but for some reason when I go on BeamMP and click the download server my computer tried to block it and when i allow it access I get this picture. Last year I was however able to make a server with no issues and now i dont know what to do!
Hi there, hope you’re doing well! 
Well, lots of things has changed since, a year is a century in computer years. Firstly, now servers require an authentication key, this is an anti-spam measure. You can obtain one from the BeamMP discord server. Secondly, now server configs are stored in a .toml config file format in lieu of the ancient .cfg. You can read more about this on the mod’s Wiki, here. Thirdly, considering you have had a server running before, issues as simple as this need of you not much but just a bit of reading.
Have fun and take care! 