u/Due-Meringue1859

I think that i will have to take a drug test for my summer internship. I am not 21 but have been a chronic smoker for the past several years. The internship starts in less than a month and i am pretty confident i will have to do a pre employment drug screening. I do not know what to do or how to pass. Is there a way I can figure out what type of test it will be? If it is a pee test am I better off trying one of those detox drinks while quitting now or using a friends clean pee? What will happen if I fail?