If your web-based software is defaulting to your phone's speaker instead of your connected headset, it is likely a browser permission or "handshake" issue. Use the steps below to fix the connection.
The "Re-Sync" Method (Most Effective)
The fastest way to force a web app to recognize your headset is to disconnect and then reconnect your Bluetooth while the browser tab is still open.
This "nudges" the Chrome browser to recognize the headset as the active audio source for that active session.
Browser Permissions
If the re-sync doesn't work, ensure Chrome has the right to use your hardware:
In Chrome, tap the three-dot menu (top right).
Select Settings, then Site settings.
Tap Microphone and ensure it is set to Allowed.
If you previously blocked the site, you may need to Reset permissions for that specific URL.
System Audio Profiles
Check that your phone isn't limiting the headset to "Calls only":
Go to your phone's Bluetooth settings.
Tap the gear icon next to your headset.
Ensure both Media audio and Call audio (or Input) are toggled ON.