Q: Can I change my payments to Paypal instead of my charge card?

See the quote below from Payment methods you can use in the iTunes Store, App Store, and iBooks Store - Apple Support

The available payment methods vary by country. You can typically use these methods:

• Credit cards
• Debit cards
• Content codes
• Store credit, including iTunes Store Gift Cards, Gift Certificates, and Allowances
• PayPal (requires the account to be linked to a credit card)
• China UnionPay (requires SMS PIN for setup)
• Mobile phone billing (through supported carriers)
• Bank Cards (China only)¹

If your PayPal account is liked to a credit card and the PayPal option is available to your country, the following has instructions on how to change: Change or remove your Apple ID payment information - Apple Support