Unet Multiplayer Not working

I have developed a multiplayer game (Learn from this tutorial: - YouTube)
My game is working fine when I have created “internet matchmaking” On the same networks Like my mobile and computer is connecting with the same internet
but when I connect One device with different network and create an internet match and on another device, I try to find Internet match nothing find
no match found over the Internet with a different internet connection
please help I am stuck from last 5 months

Set Unet from unity services it seems it is not configured there? Check is your game perfectly running on LAN?