frontend not calling backend properly

**Describe the bug**
When I open the frontend and enter a prompt in the chatbox, it displays a “fetch failed” error. In the developer console, the error appears under useChat.useAsyncCallback[runChatCompletion].

**Expected behavior**
After entering a prompt in the chat interface, it should display the response to the prompt instead of showing an error.

**Screenshots**

**Desktop (please complete the following information):**
- OS: [e.g. macOS, Linux, Windows] -> Windows
- Python version(python -V): Python 3.13.7
- ADK version(pip show google-adk): 1.18.0