This is a very stupid mistake that I have done in my life.
When you first time connects with Bluetooth then you will see WH-H910N(h.ear) but after that, if you want to connect it with another device Just press the power off button for 7-10 seconds and you will hear Bluetooth pairing on and you will see the Bluetooth headphone device found in your Bluetooth searching devices.
I installed/upgrade/degrade many libraries to connect my headphone but after my stupid mistake, I connect it with native Bluetooth provided by ubuntu itself.
I answered this question because no one will do it this mistake in the future.