In order to connect Server Offline server you can use direct Steam connection link, or copy console command and paste it in Rust console.

Connect via Steam

Once you press button above, Rust will be launched and try to connect server. This method doesn't work properly in some browsers.

In order to connect via in-game console, while you in Rust main menu press F1 and paste code above.

In order to connect GAIA 1000000X - NoBP|MyMini|Kits|Clans|PVP|Skinbox server you can use direct Steam connection link, or copy console command and paste it in Rust console.

Connect via Steam

Once you press button above, Rust will be launched and try to connect server. This method doesn't work properly in some browsers.

In order to connect via in-game console, while you in Rust main menu press F1 and paste code above.