Send "Origin" (LLA) to PX4 manually (no GPS)

I’m writing a small application that communicates with PX4. However, I’d like NOT to use GPS.
So I turn it off (EKF_AID_MASK to be 24), and then I’m trying to send the initial Global Position, manually.
Currently, I can’t find a way to do it.
Is this possible?

Let’s see if @tumbili can answer this, or @bresch.

I don’t think that’s currently possible. You would need to make some changes manually.