Contact person: Business Client

Phone:Show

Email:Show

Location: Johannesburg, South Africa

Budget: Recommended by industry experts

Time to start: As soon as possible

Project description:
"I’m midway through the Meta onboarding flow for WhatsApp Business and I’m stuck at the “Generate Certificate” step. The portal keeps throwing the exact message: “Something went wrong. Please try again later.”
Here’s where things stand:
• My phone number is added, verified, and the display name is approved.
• The number shows as un-registered.
• When I try get an Access Token using the button on their portal, it says "Unsupported post request"

Once that hurdle is cleared, I simply need a proof-of-concept in PHP—tiny scripts that send and receive basic WhatsApp messages using my verified number so I know everything is wired up correctly and can continue with my project.

I do have access to the official Meta documentation, but I haven’t had time to read through it in detail, so I’m leaning on your expertise to:
1. Diagnose and resolve the certificate error inside the Business Manager / Developer portal.
2. Register the number fully.
3. Hand me a minimal, well-commented PHP example (curl or the Meta SDK is fine) that successfully delivers a single test message.

Please keep the solution lightweight, clearly point out any token or credential placements, and give me a quick rundown of any permissions or webhooks I should enable so I can extend it later." (client-provided description)