Since you do not have the Fast Travel ability yet, you will have to venture into the depths of the Zelda map to find this Shrine.
Similar to other shrines, the In-Isa Shrine has its own puzzle to solve, and considering how unique these objectives are, you will have a difficult time solving them.
Where to find the In-Isa Shrine in Tears of the Kingdom
The In-Isa Shrine is arguably the hardest shrine out of the three in Tears of the Kingdom. To reach the location, you must head southeast from the Ukouh Shrine to find a rail. Use your Ultrahand ability to combine the platform and hooks to the rail and slide down to the end of the area.
As you slide down to the next area, you must combine the three logs at the bottom to create a single large log which you can use to create a bridge over the broken path ahead.
Head south to come across different Constructs that help you prepare meals to restore your health. This is an optional task and doesn’t need to be completed during the search for the In-Isa Shrine.
As you head south, you must drop down into the waterfall below and make your way to the dry land on the left side. Here you can use Ultrahand to combine 2x logs and place a sail on them to create your own boat which you can use to sail across the lake to the Island where you will find the In-Isa Shrine.
How to solve the In-Isa Shrine puzzle in Tears of the Kingdom
As you enter the shrine, you must destroy the stone wall that blocks your path. Start off by creating a Boulder Hammer.
You can do that by picking up the Claymore Sword from the entrance to the shrine and using your Fuses ability on it.
Go to the Boulder and merge it with the sword to create the Boulder Hammer which you can use to break the stone wall.
In the next area, you must create a Burning Arrow by combing the Arros with the Fire Fruits on the tree. Once created, shoot at the vines on the wall to drop the chest with the small key inside. Collect the key and use it on the main door.
This portion of the area will have an enemy in it. You can kill him from a distance and use the Boulder Hammer you created to break the stone wall to reveal the green shrine upstairs.
Interact with the shrine and regain the power to your arms and get rewarded with the Light of Blessing. Exit the shrine to receive the Energy Cell and move onto the third and last shrine of the Closed-Door main quest Reach Gutanbac.