Bringing CTO Co Founder with TN Visa

My team and I are working towards MVP and need to bring on another Co Founder/CTO to the company to get there. The person I would like is on a TN visa.

Is it possible to offer them shares/equity in the company and have them work on the product? We are pre seed so this person would not be paid. What are the laws around this, is it legal, can I make this happen?