No, you will not “have to do it”. Either they can afford to pay a qualified person to do it, or they can’t. If they can’t afford a more expensive person, they definitely can’t afford to fire you. You are the cheap one.

Think about it: if they put themselves in this situation, they are going to end up cleaning it themselves. “Need money for rent and food”? If you have a crappy minimum wage job, you have the power. Literally no one above you wants to do your work. You can definitely tell them “no”.