Guest checkout for one-time payments
If the Offer is a one-time payment, your customers 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:
Account required for recurring payments
If the Offer is a payment plan or recurring subscription, your customers will be prompted to log into their account or create an account to checkout with PayPal: