Creating user with mobile number verification and login with just OTP

Here is our actual requirement

User should be able to signup from our app with the following details

  1. First name
  2. Last name
  3. Email
  4. Mobile number (Includes country code)

Then OTP verification should be done, then only registration should be successful.

Login should be purely OTP based so the form contains only the mobile number field, nothing else.
When the OTP verification is successful, user should be logged in and token is returned.

When I make an API call to fetch user details, I want to get the details user has provided when signing up. Also there should be a sign out option. that takes the user out of the app.

How the Firstname, Lastname, Email and Mobile number fields are saved in database? Are they encrypted and secured?

Can someone help me to know if my requirement is possible with Okta, if yes, can you please guide me on that with some references/steps.