Tensile foam, can't grab point I made


Hi, I’m newbie in terms of grasshopper and kangaroo. I’m trying to make a tensile structure like soap film by otto. I tried to grab the point on mesh and pull it but it didn’t work.

I even don’t know how to make a point on the mesh.
Does anyone know tips on this issue?
Thank you for your help!

please post your gh file with internalized geometries