Netflix accepts PayPal as a payment method as long as it is available in your region. If you do not see PayPal as an option when signing up or when you are updating your payment method, PayPal payments are not available in your region at this time. Feel free to check back periodically to see if this option becomes available.
If you are having trouble getting Netflix to bill through your PayPal account, PayPal can provide the most up to date information on the types of payment they accept for Netflix transactions in your region.
If you need to update the payment method on your PayPal account, PayPal.com can help walk you through that process as well.