Try peeing into the cup mid- or end-stream, not immediately. How you pee into the urinalysis cup matters. Try peeing a little bit into the toilet, and then direct your stream into the cup when you’re nearing the end of your stream. Pee near the end of the stream is supposed to contain fewer metabolites than pee at the beginning.
Try also to pee several times in the morning before taking the drug test. Your pee will contain more metabolites if you haven’t already gone to the bathroom before you take the test. Be smart and chug some water first thing when you wake up the day of the test.