3d mesh generation in OGS5

Hi, I’m trying to make 3d mesh to simulate the river flow. Is there anyway that I can make 3d mesh from the surface from points I have made?
Actually, I tried Data Explorer and GINA. But, I coudn’t make what I wanted…
I’m totally noob, so it would be grateful if you show me the appropriate guide to make 3d mesh. Thanks

These are the points what I’ve made.

This is the error what I’m struggling with.

And this is what I want to make.