Infinite hallaway

I don't know how to actually make this as I'm still learning.

First create your dimension and biome(this biome will generate only in the custom dimension) and set all the blocks to air

Second you'll have to learn this

https://mcreator.net/forum/62582/guide-random-generated-structures

Then you'll need to find a way to make the structure generate when the player enters the dimension.

Idk how to do this as I'm still researching it but the main thing you'll have to learn is how to make connected structures

If the tunnel is the same thing all around, you could just make a procedure that runs whenever you're in the dimension and you're facing the direction of the tunnel and it will autoplace whenever you walk forward up to a certain distance.