How to add the bridge:

1. Append Harmony Arch Bridge.blend to your Blender project.

2. Create a Path (Curve/Path) and make sure the path have only two vertex points.

3. Go to Modifiers and search Harmony Arch Bridge, a Bevel modifier after this is recommended but not required.

How to move the pinned points:

To move the pinned points, in edit mode, it is recommended to have always X = 0 in local space in Edit Mode, move only Y and Z. To rotate the bridge around the Z-axis, do it in object mode, not edit mode.

Happy blendering!