Can i rent out my basement/apartment ?

I live in a owner occupied Duplex in Philadelphia which also has a finished basement which is apartment style but couldn’t be zoned as a third unit. Basement has a huge 1 bedroom with closet space, full kitchen, full bathroom and also had separate entrance. I recently rented it out to a family member but now they are moving out. What’s a way i can rent out to someone else & If so should i do a written lease or just a verbal agreement ?