you need a world portal igniter on a nether portal, it takes you to my sponge world. This is the first mod I have ever made, I made it using mc creator, it is a good way to make mods in my opinion. It took me over 1hour to make. I hope you enjoy! If you want to know more go to About MCreator - Minecraft Mod Maker | MCreator
for 1.16.5 the thing is called sponge world to light the portal. Type it up in the place you get your items this was made because people might have a laggy pc.
In the new update do /bye just try it
I meant / to in the new up date called tp