Here is how to set up Face ID (face recognition) or Touch ID (fingerprint recognition) again.
Open the Settings app, tap "Apps", and select this app from the list of apps.
Then turn on Face ID or Touch ID.
If the option isn't there, tap "Face ID & Passcode" in the Settings app, open the list of other apps under "Use Face ID For", and enable Face ID for this app.
If the option still isn't there, open this app and turn the "Passcode Lock Settings" option off and back on in the settings screen. Then set up your passcode again.
If that doesn't help either, please try reinstalling the app in a way that keeps your data intact.
To do this, open the Settings app, tap "General" → "iPhone Storage", select this app, and tap "Offload App".
This removes the app while keeping its data on your device.
Then find the app on the App Store, reinstall it, and check whether Face ID or Touch ID works.
If the issue persists, please tap "Contact Us" in the upper right to contact us.
Thank you.