Video source: https://youtu.be/mjuoSk05rUI
First of all you will need Mod Menu to be able to configure this mod for Fabric. Grab it Here
Get the Immersive Portals Fabric mod for 1.18.2 from Here
Note: OptiFine may not be compatible. Check the Mod's main page for more information. Sodium/Iris may not be full compatible. Disable them if you are getting crashes.
Any issues, then just post a comment in above YouTube video link's comment section.