Want to create OTP based login (without 2FA)

I want to implement OTP based Login in Keycloak but it should be without 2 Factor Authentication.

In this it should ask for username/mobile/email in the first screen form and after validating the that existing user/mobile/email it should ask for OTP sent to his/her mobile/email.

Once OTP is validated that user should be logged-in.

Would be appreciate if anyone could help me on this.

Thanks in advance