Problem with steamwoks

Hello
I am trying to create a multiplayer game with steam connection, did everything that has this site link text. everything seems to work fine, however when you open the game, steam shows I’m playing a game called Spacewar, and when my friend tries to join my departure, the screen goes black

Your game is not registered in Steam, you using test appID 480 which in Steam database is registered as “Spacewar”

https://steamdb.info/app/480/

I’m not sure what with session joining but or Steam don’t support that on 480 appid or there some entry level problem in you game or game simply don’t run on your friend computer. (is he able to run game normally?)

appID 480 is only for testing in steamworks, but I can use to create server of my game?

I created a project with the multiplayer functionality. LAN it works, but when I put all the steam sdk. the server is not found for my friend, and if you try to connect, the screen goes black.