Add Google reCAPTCHA to Mobile login page

I need Google’s reCAPTCHA v2 wired into the registration flow of my mobile app to block automated account creation. When a new user presses “Sign Up,” the challenge should appear, return its token, and let the server validate it before any account is written.

The codebase is already live; you can plug into the existing react native project—or suggest an equivalent wrapper if you prefer React Native or Flutter. I’ll supply the current registration screen code and backend endpoint; you bring the reCAPTCHA keys, client-side widget, and server-side verification.

Acceptance will be based on:
• reCAPTCHA v2 challenge renders smoothly on the registration page of the mobile app.
• Token is verified on the server, and invalid or missing tokens are rejected.
• Clear hand-off notes so I can rotate keys or adjust thresholds later.

Please tell me how long this should take you and what access you need so we can start right away.