Drug test

Follow up to my other post. I got a job yesterday! Hazzaahhh! I know I’ll get the full Reddit shame which is deserved but I was drunk at a concert this past weekend and wasn’t thinking about jobs lol or drug screens… so I decided to smoke weed. I start June 15th for my job and have to take a drug test tomorrow. I did an at home thc test and I tested positive. I don’t smoke at all maybe once a year. Would using synthetic urine help from a smoke shop help? My brother used it for his job for ICE and passed. How can I get the THC out of my system? I remember niacin and lots of water helping. Thoughts?