Convert 2d object in 3d

Hello. I saw the game Draw Climber the other day and wanted to figure out how 3D volumes are obtained from a drawn 2D line.
While I have a problem. Maybe someone knows how to do this, or at least which way to look?
Thanks in advance to everyone and sry for my english anyway)

Hi, as a solution, you could save key points of your drawn curve/shape (where your line bends) and generate mesh or lines based on this data.
The same technic is useable for creating colliders for the correct collision.

Also, you might use the asset for the easy converting sketch which you draw in the canvas region to 3d mesh.

asset link
video example