You can do this with purchases in the parks charged to your account with your MagicBand, but not with mobile orders. Completely different system.
How did you do this? Was it an egift card? I don't think you can add a physical Disney gift card to Apple Wallet.
Yes, you can charge purchases in the parks to your room account with your MagicBand. But mobile ordering is a completely separate system in the
MDE app. Anyone can use it, not just Disney resort guests. MagicBands are not involved in any way.
Your payment options for mobile ordering are a linked credit or debit card (this can be the same one linked to your Disney resort room account, but does not have to be), Apple Pay, a Chase Disney Visa rewards card, or Disney gift card. For the last two options, you have to re-enter the card numbers for each purchase. I overcame that convenience by keeping my gift card number(s) in a note on my phone, and just did copy/paste for each purchase. Worked great.