Ho to add obstacles to GENERATED (not baked) NavigatrionRegion3D

Godot Version

`v4.5_stable

Question

How do i add an obstacle to my NavigationRegion3d which i generated using the Mesh → generate Navigation-Mesh? I tried adding a NavigationObstacle to my bench and all kinds of stuff. I cant rebake the NacigationRegion because i generate them through the editor (view picture)


i want to make sure the benches are not walkable for any agend

thank you in advance im loosing my mind here