This cannot be stressed enough. It's not an option for a company to pay you for your work. It's a legal requirement. Do not work for free. An internship is not

This cannot be stressed enough. It's not an option for a company to pay you for your work. It's a legal requirement. Do not work for free. An internship is not employment. It's something a company does that's supposed to benefit you educationally. It's not a way for a company to get free labor. It took a lot of fight to get labor laws in place in the United States and they exist for a very good reason.