Is there a way to restrict certain addresses from completing forms?

We are selling raffle tickets and are governed by lottery licensing that states we can only sell to individuals geographically located in our province.

Is there a way to block people when they attempt to use an out of province address?

There no way to block people from submitting the form based on the province.

However, you may create a conditional question, to choose the state first. A drop-down field will help here. If it matches with your state you allow them to fill the rest of the form else you can redirect them to the custom thank you page.

I hope this helps. Let us know if you have further questions.