I have sent a paypal request to a client who is not a PayPal user - She received the request but there is no "Pay Now" button or even a link to take her to payments.
Thank you for asking your question in our community. Sorry that you did not receive any response sooner.
In this case, the buyer would need to open an account in order to pay you through PayPal. When she has done this she will be able to view the invoice in the account and pay that :).
