At the start, follow the path west from the main entrance to the Fortress. You’ll enter the Reactor District first, and make your way west, through the groups of enemies. Right before the last curve of the road, just underneath the tall bridge, is a small entrance to the Skybridge. This is right from the tall Clockwork tower, with several long pipes.
Once in Skybridge, continue forward and keep to your left. Soon enough, after a long straight path, you’ll come up to a small crossroad. Keep going forward, toward the metal pole. This pole is at the center of this metal-fenced area. Next to it, on the very edge of the plateau, on a small pipe is the Skybridge Skyshard.
On the lip of the Skybridge.
Sand Kingdom Moons - Super Mario Odyssey Power Moons