HELP ASAP ‼️‼️‼️‼️‼️‼️

I need to clean my system ASAP, I have no clue on how much time I have exactly, but someone I know offered me a job that’s really good and the process is moving way faster than I thought, and there’s like a 90% chance they’ll piss test me, I have no idea if they’re gonna do it at my interview (which hasn’t been scheduled yet so idk how much time I have) but my friend talked to his boss tonight so I should have an answer by tomorrow! I’ve been smoking for years, and fake pee is kinda out of the question for me. I’ve been drinking water but should I take niacin pills? Anything? HAAALLLLPPPPPPP