You could suck dicks, or jerk dudes off. You could sell your semen to a sperm bank or if you can’t nut, just collect some and sell it instead. Probably sell pictures of your genitals on the subway. Better yet, what if the sperm bank is hiring? You could be the dude who tastes all the samples to make sure they’re not poisoned.
There’s probably other ways but that’s all I can think of rn.