Update app.py

app.py

@@ -443,7 +443,7 @@ with gr.Blocks(css="footer {visibility: hidden}") as app:
     generate_btn.click(
         fn=generate_image,
         inputs=[prompt_input, structure_image, style_image, depth_strength, canny_strength, style_strength, steps],
-        outputs=output_image
+        outputs=[output_image]
     )
     
     gr.Markdown("""