Some questions about Bluetooth devices

[gaoruiqing187]

When I connected to the phone using a Bluetooth headset, I set the system Bluetooth mode, and I did use the headset when playing audio. But when I call the linphone to make a call, it's the phone's microphone，How do I set it to Bluetooth。

This is my code to set the system mode。
do {
try AVAudioSession.sharedInstance().setCategory(.playAndRecord, mode: .voiceChat, options: [.allowBluetooth])
try AVAudioSession.sharedInstance().setActive(true, options: .notifyOthersOnDeactivation)
} catch {
print(error.localizedDescription)
}