Sound wont work through Bluetooth in Ford Explorer
Your Explorer has/had a 36 mo/36000 mile bumper-to-bumper warranty. If you’re within that time/mileage take it to a dealer. If not, a good mechanic or possibly a car stereo shop can probably sort it out.
Additionally you’ll want to make sure your bluetooth is working properly on your phone. A lot of BT problems are on the device side, not the receiver.