fix API_URL

app.py

@@ -16,7 +16,8 @@ import requests
 from PIL import Image
 
 # API Configuration
-API_URL = os.environ["SERVER_URL"]
+
+API_URL = os.environ["API_URL"]
 
 TOKEN = os.environ["API_TOKEN"]
 
@@ -477,6 +478,8 @@ def process_file(
             headers=headers,
             timeout=1000,
         )
+        if response.status_code == 404:
+            raise RuntimeError("Invalid URL")
         response.raise_for_status()
 
         # Parse API response