how can i register telnum without firebase otp i will use own otp service?

[Mehmet HALICI]

Hello,

I am developing a mobile application with Flutter.

I will use firebase but firebase phone authorization sent SMS and sender cannot be edited so I create user collection but now I am worried about firestore rules.

What should the rules be?
 or how can i register firebase phone number auth without firebase otp i will use own otp service?

Thanks.