diff --git a/auth/server.py b/auth/server.py
index ea5aa84..cc8b07f 100755
--- a/auth/server.py
+++ b/auth/server.py
@@ -259,7 +259,7 @@ class HTTPRequestHandler(BaseHTTPRequestHandler):
 
     def root(self):
         self.send_response(HTTPStatus.NO_CONTENT)
-        self.send_header("X-Authlib-Injector-API-Location", server_url + "/ygg")
+        self.send_header("X-Authlib-Injector-API-Location", self.config["server_url"] + "/ygg")
         self.end_headers()
 
 if __name__ == "__main__":