Using external GPS device unity application

I am developing an applciation for android using Unity3D. My application usnig GPS location service of unity.

And I need high accuracy location in my application. So I have an external South Galaxy RTK device. And I downloaded an applciation named GNSS Commander that connects to South Galaxy RTK device using bluetoth and mocks the phone GPS.

After I connected to device, does Unity use the external device or does unity always uses internal GPS device of phone?

What does Input.location.lastData gives me? Internal mobile device GPS location or external RTK GPS device location.