We are working on a mobile app that offers 'give and receive' advice (concerning relationships, life questions, and so on). In the onboarding flow, we allow users to choose how to create their account - via email & password or phone number. Our management team insists on asking the user for their email address if they chose to create an account using their mobile number. I already know when to ask this (after they approved the OTP code we sent them), but not sure how to do it - how to present it or even phrase my request? In most cases, the user does not expect to also share their email if they just signed up using their phone number...what do you think is the best way to do this?
As per my understanding of the use case, in both the cases the end user's email is mandatory. So, you can try to approach a way where both phone and email id should be asked while registering so that it will reduce the additional step when user opt for registering via phone number.
After the OTP approved, you can ask them like "Login with your email account and enjoy the experience"/ "Happy to know about you and help you" and ask the first name, last name and email.
Hope this helps.