Cannot complete purchase in ACPC

Hello! I have attached screenshots. Actually, I have already corrected the issue but perhaps the post could help others. After trying restarting phone, deleting and reinstalling app, and contacting Apple support, I remembered a prompt after updating my phone to re-sign in with Apple ID password. I had signed into my account in the App Store so I didn’t think that would have an impact but sure enough I went to my iPhone settings and found an alert at the top stating some services would not be available until I signed in again. I did that and proceeded to complete the purchase and was successful.