How can I fix the issue with form submission and data capture on a Webflow site when using OTP verification through WhatsApp?

If you’re using OTP verification via WhatsApp and your Webflow form is not properly submitting or capturing user data, the issue usually involves third-party integration conflicts or missing automation steps.

1. Verify Third-Party OTP Service Setup

• Ensure your OTP service (e.g., Twilio, MessageBird, Firebase) is properly configured and integrated to handle number input and send OTP via WhatsApp.
• Confirm that the user's phone number is correctly formatted and compatible with WhatsApp delivery.
• Test if OTP is being sent independently of the Webflow form, via Postman or a simple test endpoint.

2. Use Custom Form Handling with External Scripts

• Webflow forms don't support backend logic like OTP validation, so the flow needs custom JavaScript and an external server or service for OTP verification.
• After users input their phone number, use custom JavaScript to call the OTP verification API, and only after success, enable the form submission or show the rest of the form.
• Use a tool like Make (Integromat) or Zapier to trigger backend OTP verification before allowing form submission.

3. Prevent Premature Form Submission

• In your Webflow form, disable the Submit button until OTP verification is successful.
• Use JavaScript listeners to detect when the OTP is entered and verified, then programmatically enable the Submit button.

4. Store or Pass Verified Data for Submission

• After successful OTP verification, ensure you store the verified data (e.g., phone number) in a hidden form field before submission.
• This allows the verified value to be sent with the regular Webflow form submission to the CMS, Zapier, Make, or email.

5. Use Webhooks or APIs for Final Submission

• If you're bypassing Webflow's native form submission and using a custom endpoint:
• Send the form data using fetch() or Axios to a third-party service or database.
• Ensure your external server (e.g., via Vercel, Supabase, Firebase Functions) handles both verification and data capture securely.

6. Debug Using Browser Dev Tools

• Use browser Console and Network tab to check for:
• Any failed API calls (check HTTP response codes like 403 or 500).
• JavaScript errors that might block the form logic.
• Form submission events being fired prematurely or not at all.

Summary

To fix form issues with OTP via WhatsApp in Webflow, you need to integrate OTP verification outside Webflow using custom JavaScript and an external service, prevent form submission until verification is complete, and pass verified user data into hidden Webflow fields or via a custom submission handler. Webflow alone can’t manage OTP logic — custom scripting and external APIs are required.