Currently, FaceID and Biometrics sign-in are not available. These security options were once a feature, however, they have been removed for the time being.
We anticipate this feature will return one day but there is no indication as to when that would be.
If security is of concern, a recommendation would be to sign out of EveryDollar after each use (click HERE for instructions) by tapping Profile and then the Sign Out option.