Doesn't vibrate in iPhone

[dark-chocolate]

I am using below code

// Check if the device can vibrate
              bool canVibrate = await Vibrate.canVibrate;
              print("canVibrate = ${canVibrate}"); // returns true

              Vibrate.vibrate();

Still it doesn't vibrate in real device.

Tested in iPhone and iPad pro running 12.0.1