Using the Ramp Prefabs

Under the Levels\Ramps\Parts you will find .glb files of ramp prefabs with collision to use in map maping

Simply drag and drop these GLB files into the Level node, then position, rotate, and scale appropriately.

There is an example character under Assets\Characters\Y-Bot\Y Bot.tscn to check scale. You can use the View Gizmo in the top right of the viewport to focus the camera on the X/Y/Z axis