"To begin, you can go to “Options-Chat Settings-Battleground Voice Chat” to activate the voice chatting function.
During the battles, click on the microphone button next to the mini map start voice chatting with your teammates.
Apparently, the players cannot hear the others talking or the teammates cannot hear them talking.
On the other hand, someone pointed out that maybe the teammates were not selected to try out the voice feature. Another problem that occurred with the in-game voice chat feature is those who were chosen cannot turn it on in their settings.
This will help players complete their jigsaw event before time runs out.