Update app.py

fix typo again

app.py

@@ -87,7 +87,7 @@ async def capture_screenshot(image_type: str):
             image_url = get_image_url(image_type)
         else:
             #image_url = url
-            Return "No image found"
+            Return f"No image found"
         
         print(f"Opening image from p5 sketch: {image_url}")
         await page.goto(image_url, timeout=120000)  # Wait for the image page to load