Follow these steps to connect your Minecraft server with Playit.gg
When you start your server, you should see a message like this:
[00:00:00 INFO]: [gg.playit.minecraft.PlayitKeysSetup] trying to exchange claim code for secret
[00:00:00 INFO]: [gg.playit.minecraft.PlayitKeysSetup] failed to exchange, to claim visit: https://playit.gg/mc/1a2b3c4d5e6f7g89
Click the link shown in your server console.
If you already have a Playit.gg account, log in. If not, click Create and choose Use a guest account or create a regular account.
Click Continue.
Click Add Agent.
Wait for about 5–30 seconds.
Click View Tunnel.
Copy one of the IPs shown and join your Minecraft server!