The Mayachin Shrine can be found near the Exchange Ruins north of the Hyrule Field Skyview Tower.
To clear the shrine, you’ll need to complete the A Fixed Device challenge. To start, head down the stairs riding the spinning platform to the other side and make your way over to the giant pinball area. Attach one of the slabs to the spinning device and then one of the stone pillars to that.
Look for the yellow stone sticking out of the ground overlooking the area then step on the platform to the left of that to reveal a target. You’ll then need to hit the yellow stone to cause the spinning device to move. Time this with when the ball is close by (about at the second white square on the ground from the device) to launch it up the ramp and hit the target. This will open the gate allowing you to reach the altar and obtain your Light of Blessing.
Before heading to the altar, there is one chest you can grab. It’s located behind a gated room. To reach it there is a target on the right side of the room you’ll need to hit. Currently, it’s blocked by a hanging slab. To remedy this, stick two spikes on the back of the slab towards the top then use the Ultrahand ability to stick them into the ceiling above the slab. This will clear the path allowing allow for the ball hit the target. Return to the yellow stone and hit it to send the ball to the right target. You’ll need to wait until the ball is almost next to the spinning device to actually send it right. When you manage to hit the target, the gate will open and you’ll be able to loot an Energizing Elixir from the chest.
When you’re ready, approach the altar to receive your Light of Blessing. Click here for more guides and walkthroughs on The Legend of Zelda: Tears of the Kingdom!