Why can't I talk through the helmet when it’s connected to the app?

Why can't I talk through the helmet when it’s connected to the app?

1> Check whether the Bluetooth earphone on the helmet is connected to your phone’s Bluetooth. If the connection is normal, go to step 2.

2> Switch the voice channel in settings in the upper left corner of the intercom interface.

Questions about joining a group
How do I quickly join a group and use the intercom function? I am not receiving message from group members. How do I fix it? Why can’t I send a voice message? I cannot join a group. How do I solve this? Why do I lose sound when I connect to the intercom? iOS group cannot send voice?