Update app.py

app.py

@@ -56,6 +56,10 @@ def infer(
 
     global pipe, current_model_id
 
+    hf_token = os.getenv("HF_TOKEN_SPACES")
+    if hf_token is None:
+        raise RuntimeError("HF_TOKEN_SPACES is not available inside GPU worker.")
+
     # reload pipeline if user picked a different model
     if model_name != current_model_id:
         pipe = DiffusionPipeline.from_pretrained(