The correct way to connect to remote SQL Server (without opening UDP port 1434 and enabling SQL Server Browser) is to use ip and port instead of named instance.
Using ip and port instead of named instance is also safer, as it reduces the attack surface area.
Perhaps 2 pictures speak 2000 words...
This method uses the specified port (this is what most people want I believe)..
This method requires opening UDP port 1434 and SQL Server Browser running..