instantiate objects within an area

how can I instantiate objects within an area?

The area is referencing a list of points, such as the one in the image, which may vary in the number of points.
the list of points is already created, I even generate a mesh, triangulating the points instantiated in each click.

but I wonder how I can instantiate objects within that area.

it occurred to me to instantiate objects within a trigger (which would be attaching a collider to the mesh created) but it did not work, or maybe I did it wrong.

any ideas?

any chance this was figured out?

Any updates on this one? @gonzalitosk8