**Requirements:** two-factor verification on (section 2). 1. Go into your **Profile** and find the **"Channel-linked access"** panel, below "My API keys". 2. On the **WhatsApp** row, tap **"Link"**. 3. Declare **your own WhatsApp number** — the one you're going to chat from, not the business number: choose your country in the prefix dropdown (searchable, with your agency's country as the default value) and type your national number, without the prefix, in the field next to it. 4. Tap **"Continue"**. **Result:** the modal moves to a second step asking you to send, over WhatsApp, the code from your authenticator app — with a **10-minute** window to do it (section 5 for the detail of what happens in the chat itself).