Please check if the microphone is allowed on your browser:

Edit the Twilio number - Outbound Call Timeout - Make sure it's more than 20 seconds and more so it will dial for longer.

Please check if there are any Google extensions (VPN) that might block the call dialling. We could try to use the Guest browser of Google chrome where there are no other extensions. And login to HL from the guest browser to make a call.