Is there a way to join player in other network without lan connection with him?

If i can, then how to do it?

 

AFAIK LAN connection doesnt work with different networks.

If you want to connect with someone on other network you can:

-Port forward: Open a port on you router so it doesnt block connections on that port.
-Host a dedicated server on Azure, AWS, Google Cloud… and both players connect to that server.
-Use a relay like Steam, Photon, Epic or Unity.

 

what do you mean by "unity"?

 

Unity relay

 

Is there a free way to do non-lan connection?

 

Port forwarding is completely free

Hosting a server can be free (with limits):
-With Azure and AWS you have some free hours every month (depending on the region and how much cores the server has)
-Google cloud offers a free cluster

About relays:
-Steam costs a one time fee (100$) which includes launching your game on steam. But you can use app id 480, which is a free app id for developers to test (if you use this keep in mind that there are a lot more devs doing it, and your lobbies can appear on their lobby list and vice versa)
-Photon Realtime has 20 free CCU, and you have to pay as you get more.
-EOS is free, but a nightmare to use.
-I dont know about Unity Relay, but I think its free until you get X number of CCU.

This relays can be considered too low level (I dont know about unity) and a little bit hard to use, so there are some transports for networking solutions that act like wrappers for them:
-Mirror has a Steam and Epic transport.
-Photon PUN, bolt and fusion are built on top of realtime.
-Fish-Net has a Steam transport and a Epic transport will come soon, and I think that a Photon realtime transport is planned.
-Netcode for gameobjects has a Steam transport and a Photon realtime transport.
-Riptide has a Steam transport.

 

I think it uses Photon PUN, but it will be a better idea to use fusion.