Sending a fetch request while connected to an iOT device without internet

Question

I'm developing an iOS app using Ionic (JavaScript Framework) and I'm connecting to an Iot device and sending a fetch request to it.

If my phone doesn't have a cellular connection, the fetch fails.

This is the process:

1. Turn on Iot device

2. Use app to connect to device access point

3. Send fetch request to device

    try {
      const response = await fetch('http://192.168.1.1/');
      // handle response
    } catch(err) {
      console.log(err);
      // handle error
   }
   

4. Fetch fails

Is there a way for the fetch to work when connected to an access point without internet? Are there any other libraries that might help me achieve this?