From the side panel on the left, click on WhatsApp to expand it and Click on API Setup
Click on Configure webhooks link from Step 3
Click on Edit button in the Webhook section. This will open a Dialog with the title Edit webhook's callback URL
Enter https://stage-askribe-askribe-ohlibf5r4a-el.a.run.app/api/v1/webhook/whatsapp in the Callback URL field.
Enter ozymandias in the Verify token field
Click on Verify and Save button
Now, click on Manage button in the Webhook Fields section. From the opened Dialog, select messages and click Save.
Please note, that this is only applicable for conversational flows. If you are also using workflow triggers for WhatsApp, you need to create a separate WABA app.