Your GrabrFi debit card is compatible with Apple Pay! Follow these easy steps to add it to your iPhone:
In the Apple Wallet app, tap the Add button +
Tap Debit or Credit Card to add a new card.
Tap ‘Continue’
Follow the steps on the screen to add a new card.
Verify your information with your card issuer. They may ask you to provide more information or to download an app before approving your card for use with Apple Pay.
If you have a paired Apple Watch, you have the option to also add the card to your watch.

Do you have an Apple Watch? You can also add it there!
On your paired iPhone, open the Apple Watch app.
In the My Watch tab, tap Wallet & Apple Pay.
Tap Add Card.
Tap Debit or Credit Card to add a new card.
Tap Previous Card to add a card that you used previously.
Tap Continue.
Follow the steps on the screen to add your card.
If necessary, verify your information with the card issuer. They may ask you to provide more information or to download an app before approving your card for use with Apple Pay.
Go here to get more information about this.