Use transit cards with Apple Watch
On your Apple Watch, you can use a transit card with Apple Pay where accepted to pay your fare. See the Apple Support article Ride transit with Apple Pay.
Note: Apple Pay may not be available in all areas, and Apple Pay features may vary by area.
If a preferred card is not required by a transit system, you can use a payment card in Wallet to pay for transit without double-clicking the side button. To choose a card for Express Transit, follow these steps:
Open the Apple Watch app on your iPhone.
Tap My Watch, tap Wallet & Apple Pay, then tap Express Transit Card.
Under Payment Cards, tap the card you want to use, then enter the Apple Watch passcode on your watch.