Adding a hyperlink to PayPal for member subscription for nonprofit business

We are a nonprofit operating on a shoestring.  We do not have an e-commerce.  We are a study society with very little traffic.  Our membership is less than 100 people.  We host monthly webinars for $5 my attendee and membership annual dues which can be paid via our PayPal account or by check.  We do not accept credit cards.  Can I hyperlink to our charitable PayPal account and will I be charge an additional charge from squarespace?  We are at the very beginning trying to determine what our annual fees will be to have squarespace host our .org domain.  Thanks