I need my account number to my Apple Pay

Apple Pay does not have a full account number that you have access to. You only have access to the last for digits of the number. The number is specific to each device, for example the number on my iPhone is different than the one on my iPad, even though the same device.

Your Apple Card has three sets of numbers you have full access to only one set of numbers. Please follow the steps in the support article linked to below.

How to find the card numbers associated with your Apple Card - Apple Support

The article below explains how the three different sets of numbers make your account safer and more secure.

https://www.businessinsider.com/apple-card-titanium-different-number-apple-pay-2019-8

See the following Apple Support article for information on finding your Apple Card account number: How to find the card numbers associated with your Apple Card - Apple Support