When I go to send money a message pops up that Apple Pay is unavailable

I setup Apple Pay with a debit card. When I try to send money in message, it allows me to select amount and the debit card but when I go to send it pops up, Apple Pay is unavailable. I just set the debit card a few days ago. Is there a waiting period before I can use Apple Pay? If not what could be the reason?

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