Question: Making "Landscape Layer Data" for Heigh Blend layers.

Hello everyone! I have a problem, witl layer blending for landscape. When I try to paint the landscape, the default color is removed, because the blending layers are not created.

Painted landscape by masks (Pic. 1)

Blending painting with “Height Blend” and last layer by “Weight Blend” for hand drawing (Pic. 2)

Trying to draw on the landscape but “Landscape Layer Data” existing and i get black landscape segment. (Pic. 3)

Q: How to manually create the “Landscape Layer Data” for Heigh Blend layers?

The question is still relevant.