I have a WhatsApp-on-Firebase project that works perfectly in test mode, yet the moment I try to move it to production the Facebook webhook refuses to validate. Because of that failed handshake my business phone number never goes live, messages bounce, and the whole solution stalls. Here is what I know so far: • The validation callback from Facebook is what breaks—no challenge token gets echoed back. • I am not even certain whether the webhook URL is registered correctly inside the Facebook Developer Console. • Once the webhook is solid I need the entire flow deployed so the number can send and receive messages in a real environment. What I need from you is simple: jump into the Firebase project and Facebook app settings, diagnose the validation fault, correct any URL or token mis-match, prove events are firing (messages, status updates, delivery receipts), and finally push the build to production so the phone number behaves exactly as the WhatsApp Business Cloud API expects. If you have hands-on experience with Firebase Functions, Facebook Graph API, App Secret Proof, and SSL certificate quirks, this task should be straightforward. I will grant temporary access to the Firebase console, the Facebook app, and the WhatsApp number once we agree on the engagement. My acceptance criteria are a successfully verified webhook, real-time event logs appearing in Firebase, and a live number that can exchange messages with external users. Looking forward to getting this over the line quickly.