How can i use multiple payment options for apple purchases for the same apple id?

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Recently my iPhone put Apple Pay as my default payment. I have always used PayPal. I have tried several different ways to change this. If I try to use PayPal it just says payment denied. So slowly but surely my subscriptions are expiring. Apple Music, Disney, App Store. I have googled this and am getting nowhere.

You have to manually promote the desired payment method to be the primary payment method when making the purchase. There isn't a way to assign a certain payment method to purchase certain items.