Are there any specific cards required?
For the first method, through PayPal, any cards are suitable:
Visa, MasterCard, American Express, Discover, JCB, Diner's Club, EnRoute,
UnionPay, and others.
Even Chinese users don't have any problems. Moreover, there are no problems for all of Europe, the USA, Canada, Australia, Israel, Japan, and South Korea.
The only problem arose with a Vietnamese user. I was asked how to send money from Vietnam, but I have no idea and don't know what to answer...
For PayPal, a home phone number of the cardholder's place of residence is required, which I don't have.
Have you heard of a standard debit card issued by ING Bank Śląski in Poland, which can be used to pay for purchases online and elsewhere around the world without any additional conditions or problems?