How to change navigational mesh with pawn?

I’ve got navMesh and Pawn placed in UEditor. I can clearly see that it’s affecting navMesh and area around pawn marked as unapproachable. But when I’m spawning exactly this pawn dynamicaly in game process it isn’t affecting navMesh.
As I can understand there is no way to dynamically work with navMesh?

You can now change in your project settings whether the navmesh is generated as Static or Dynamic