add comment about using api key in headless (Comfy-Org#8082)

Author: christian-byrne

script_examples/basic_api_example.py

@@ -101,6 +101,14 @@
 
 def queue_prompt(prompt):
     p = {"prompt": prompt}
+
+    # If the workflow contains API nodes, you can add a Comfy API key to the `extra_data`` field of the payload.
+    # p["extra_data"] = {
+    #     "api_key_comfy_org": "comfyui-87d01e28d*******************************************************"  # replace with real key
+    # }
+    # See: https://docs.comfy.org/tutorials/api-nodes/overview
+    # Generate a key here: https://platform.comfy.org/login
+
     data = json.dumps(p).encode('utf-8')
     req =  request.Request("http://127.0.0.1:8188/prompt", data=data)
     request.urlopen(req)