WindowsClient cant connet dedicated server via inernet?

I need to make a multiplayer game. I get the 4.19 source code and compile the source code. Then I get the dedicated server and the client. When I run in the LAN, the server is running normally. The client can find the server through the find session method. Join the server, everything runs very well, but when I put the server on the cloud server (create session is not LAN), the client running on my local can not find the server through the findsession method(not LAN), the server is open port 7777; I did For a test, I can access my Tomcat server locally through a browser; now, how can I connect to my dedicate server? Thank you very much!!

Launch your client game with server running, and in console type open (IP of your server). If that is working – problem with online subsytem.