Follow these steps to add your card to Apple Pay:
Open the Wallet app on your iPhone.
Tap the + button in the top right corner (If the button is grayed out or you get an error, you'll need to change your region to any country that supports Apple Pay. you can see a list of countries you can change your region to here: https://support.apple.com/en-us/102775).
On the app.offramp.xyz page, tap the "Details" button
Tap Debit or Credit Card on your iPhone,
Tap Continue, then position the card so it appears in the camera frame, or enter the card information manually
What to do if you receive an error:
In some cases, you may receive an error saying that your card was not added to your Apple Pay. Apple Pay may decline your card because of your Apple account's risk score.
The account score is given by Apple Pay based on things like the age of your Apple account, current fraud suspension, etc. We have no control over your Apple account's score.
We advise you to switch to a different Apple account that you own and retry adding the card to Apple Pay.