Nope... you can literally just tap and go! It’s not necessary to authenticate payments at Hop readers.
In iOS, “Express Transit” is the name of the feature that lets you use transit fare cards and other payment methods without waking or authenticating your device. Virtual Hop cards have Express Transit enabled by default. However, if you prefer to authenticate every Hop payment, you can disable Express Transit in Settings. Here’s how:
iPhone: In Settings > Wallet & Apple Pay, turn off “Express Transit Card.”
Watch: Open the Watch app on the iPhone it’s paired with. Go to Wallet & Apple Pay > Express Transit Card, then select your Hop card.