I want to make purple open mesh to closed mesh!

Hi! I have an issue! I want to make open mesh to closed mesh!
I tried to do show edge and then fillthehole and matchmeshedge. but it doesn’t work. Please help me to fix it.
Purple mesh.zip (11.8 MB)
I made this mesh file to zip file! because it is too big to upload it.

Did you try it with ShrinkWrap ?

Actually my Rhino is version 7. so I don’t have ShrinkWrap.