why cant i use paypal with itunes

Thanks for posting in the Apple Support Communities

We understand you'd like to use PayPal as a payment method for your Apple ID, and linked to the support communities from Change, add, or remove Apple ID payment methods.

Payment method availability can vary by region, but you can find supported payment methods where you're located, here: Payment methods that you can use with your Apple ID

If you're in an area where PayPal is accepted, but you're unable to complete a purchase, you may find a solution here: If your payment method is declined in the App Store or iTunes Store

We hope this helps!