Minecraft (Bedrock Edition) from the App Store
The server has a whitelist. You can't connect until the admin adds you. Tell them your Xbox gamertag — it's the name attached to your Microsoft account. They'll add you before you try to connect.
Not sure what your Xbox gamertag is? Open the Xbox app on your iPad or iPhone — your gamertag is shown at the top.
You need Minecraft from the App Store (it just says "Minecraft" — the one with the dirt block icon). It costs money if you don't already have it.
This is Bedrock Edition, which is what works with this server.
When you open Minecraft it will ask you to sign in with a Microsoft account. Use the same account your Xbox gamertag is on.
From the home screen tap Play, then tap the Servers tab at the top.
Scroll past the featured servers list. At the bottom you'll see Add Server. Tap it.
Server Name: Goat Server (or whatever you like)
Server Address: goats.sortoflikethis.com
Port: 19132
Tap Save.
Goat Server will now appear in your list. Tap it to join. If it says "You are not whitelisted," the admin hasn't added you yet — ask them to run fwhitelist add YourGamertag in the admin panel.