Setup keymap for Gizmo

How to initialize setup_keymap for GizmoGroup?
I already asked a similar question, but unfortunately after the last update those workarounds that I found no longer work for me.
I create a custom gizmo for blender 2.81, and in the blender settings you can specify under what circumstances the gizmo will work.
image
I’m interested in Activate Gizmo PRESS/DRAG, specifically DRAG.
I started searching the blender repository on github for what these settings refer to and found a few mentions WM_gizmogroup_setup_keymap_generic_maybe_drag
image
There is also this
https://github.com/julianeisel/blender/commit/2e22cfd08a0d589e8894e322ed29d5c3227ca04d

Gizmo also has Test_select. The documentation says " use -1 to skip this thing"
image
https://docs.blender.org/api/blender2.8/bpy.types.Gizmo.html?highlight=gizmo

I just can’t find a reference to describe this task.
How do I get my gizmo to react just by dragging?

There are also specific descriptions of keymaps
https://github.com/julianeisel/blender/blob/e2b0647272c7fcb94bdf3bddd6bc086b7130d757/release/scripts/presets/keyconfig/keymap_data/blender_default.py#L4817
image
image