Meta App & WhatsApp Integration Setup

I’m ready to get a Meta app up and running strictly for messaging and need a specialist who can take it from creation to fully authorised WhatsApp use.

Here’s the flow I want completed:

• Meta App creation configured for messaging, with the correct business-use case selected and tied to my already verified Business Manager account.
• Facebook Login for Business activated so users can authenticate smoothly.
• Embedded Signup (ES3) implemented on the frontend: your code should trigger the login popup, guide the business and phone-number authorisation, then surface and return both waba_id and phone_number_id.
• Token exchange handled via the Graph API, turning the short-lived authorisation code into a permanent System User Access Token.

I’ll provide any existing credentials you need; you deliver tested code snippets, clear setup notes, and confirmation that the IDs and long-lived token are working in Postman or a quick demo call.