Here's how you can add those mods on your Fedi:

1️⃣ Tap on “Mods”

2️⃣ Tap on “Fedi Mods Catalog”

3️⃣ Tap on the mod you want to add to copy the link then click the ‘x’ at the bottom right of the screen to exit the Catalog

4️⃣ Tap on the “+” at the top right of the Mods page

5️⃣ Tap on the “Paste”

6️⃣ Tap on “Save”

You've successfully added a mod 🎉