Yes, if the Offer is a one-time payment your customer(s) can checkout as a guest with PayPal. They will be redirected to the PayPal pop-up where they have the option to click Pay with Debit or Credit Card to check out as a guest:
However, if the Offer is a multiple payment or recurring subscription your customer(s) will be prompted to log into their account or create an account to checkout with PayPal: