handle encoding for json

Instead of using data=data, use json=data to ensure the requests library automatically handles the encoding for JSON:

docs/getting-started/api-endpoints.md

@@ -62,7 +62,7 @@ To ensure secure access to the API, authentication is required 🛡️. You can
           }
         ]
       }
-      response = requests.post(url, headers=headers, data=data)
+      response = requests.post(url, headers=headers, json=data)
       return response.json()
   ```