A:AnswerMENU #238 and turn it on.
To erase messages, go to the page 44 in the owner's manual: https://help.panasonic.ca/viewing/ALL/KX-TGF540/OI/TGF540_PNQX8346ZA/TGF540_PNQX8346ZA.pdf
#C
A:AnswerBluetooth connectivity not required. The handsets should be plugged into electrical source to charge the phones unless you want to play music chairs trying to charge all three phones on the base.
A:AnswerYou won't be able to pair two phone systems, but you can have the same line on both phones. Base units must be placed far from each other to avoid interference.