Hi @naresh.seth,
Welcome to the Auth0 Community!
It is not possible to use a Custom Login Page with Identifier First + Biometrics as Identifier First + Biometrics only works with the New Universal Login Experience. Using a Custom Login Page enforces the Classic Experience for login.
Please see this Community solution discussing the differences between Identifier FIrst + BIometrics and Passkeys: Difference between passkeys and Id first + biometrics flow
Best,
Mary Beth