If you hit the green flag, your mod should disappear. The code is good to go, you just have to set values to 3 variables. Read the comments in the code editor for more. NOTE: Modding is experimental for NTS 24. If you have errors, let me know. NTS 24 currently can support 1 mod, any more and the project won't run properly. Mods will not be saved when you save a game with them. If you have errors, reload the project and play without mods.
Sharing your mod: Save your mod as a remix and I will check out your mod and maybe add it to a mod collection project (with credit): https://scratch.mit.edu/projects/989658120/