Unlocking all Shrine locations in Zelda: TotK might seem like a long and tedious task. Some might take longer while others will be as easy as it can get. If you are out and about solving Labyrinths in Zelda: TotK then you might as well explore the Igashuk Shrine.
Where to find the Igashuk Shrine in Zelda: TotK
The Igashuk Shrine is located on the Lomei Labyrinth Island which is one of the many Labyrinths in Tears of the Kingdom. Every Labyrinth has a total of three sections; Surface, Sky, and Depth, and needs to be completed in that particular order.
The Lomie Labyrinth Island is located at the top right corner of the map, towards the northeast of Deep Akkala. The Igashuk Shrine can be accessed through the Lomie Labyrinth Island which is on the surface. The exact coordinates of the Igashuk Shrine are: 4664, 3686, 0129

Getting to the Lomie Labyrinth Island is also not a big deal. You can stand at the marked location on the map given below in the Deep Akkala Region, near the Akkala Ancient Tech Labs, and from there will see the island as clear as day. You can glide towards the island by jumping off the side of the cliff.

How to complete the Igashuk Shrine in Tears of the Kingdom
The only challenge here is getting to the Shrine. The Igashuk Shrine is actually easy to complete in Tears of the Kingdom.
Once you have reached the entrance of the Lomie Labyrinth Island, there are two methods. One is the straightforward and boring method that will require you to navigate the maze by following a trail of Acorns which a researcher has left.
Although this method is not difficult at all but will take a bit of time. If you want to explore the whole maze then you should go for this one.
If you are looking to save some time but also want to complete the shrine, there is a shortcut as well but you will need to have obtained Ascend in order to do this.
For the shortcut method, you can head straight for the wall with a giant red mark on its face and use the three wooden logs and push them towards the right corner (marked on the map) of the extended wall.

Now stand on top of the log and use Ascend to move through the wall and reach the upper level. You will see the entrance to the Shrine right in front of you but you will be blocked by metal bars. You will have to use Ascend again to get to the roof.
Now go towards the right and turn the corner. Look below and you will see a passage between two walls. Drop down there. Now go forward and climb the ledge in front of you. Then the ledge towards your right.
You will reach a hallway, at the end of which will be a Zonite Sword and Shield. You can pick those up while you are there. Now stand in the middle of the hallway and use Ascend to one again reach the upper level.
You will come up in front of a staircase. Go up and there you will see the entrance to the shrine, in all of its glory. You can enter and loot the chest right there. It will contain a Large Zonai Charge. Beyond the chest will be the panel to activate the Igashuk Shrine.