Help with CS:GO dedicated server

Hello everybody, i made a server following a youtube tutorial, but when i went to test it out using a 2nd computer, i only could only join throo LAN. I also tried to get in using the PC that is holding the server, which i could join throo the Community servers list, and also thro LAN. But nobody else can join it, only the PC that is holding the server can join thro the Public IP. Any help on getting the server to be able to accept players thro the public IP? BTW, the ports are sucessfully opened and i also have a server token I also tried the command "heartbeat", but still didnt do anything and when i type in "net_start" , this message pop's up : "Cannot init steam datagram client, no Steam HTTP interface"