I test the same tnt launcher on a local world, a world of my own, and it didnt work either. The problem is that is not working on survival.

is a Primed TNT summoner, if the executing entity is Evoker Fangs or a Vex. The tnt launcher was the common design with dispensers around a 3 by 3 square full of water and a button to activate the 12 dispensers, and of course i was on the middle of the water square. The Crafting Table recipe is unlocked immediately on creating a new world.

I was playing on a friend's realm on creative, and i build a tnt player launcher, i tested it (i was still in creative) and it worked, it launched me very high, it was succesful but when i tried it in survival it didnt launched me, i tested it plenty of times because i taught it was like a 50/50 chance, but no, it didnt worked. The player/mob should be launched high into the air. The player/mob is not launched high into the air. Activate the dispensers and wait for the TNT to explode.Switch to Survival mode if you are standing in the water.Stand in the center of the water or spawn a mob in the center.

How to make a tnt launcher in minecraft