Steam Advance Session - Automatic Host/join with one button

i am trying to let people create a session and also join them with one button i dont want to show server name etc all i want is if you have a party or alone and you click " play " if there is a session with maximum number already it will create another one if not join that session

i found similar topic to mine but the plugin he is using is older version and the engineini he is using cannot be copied to mine any help please

note i am not very good in english hard words will be pain to me to understand