En-Oma Shrine in Zelda: Tears of the Kingdom is a crystal shrine which ill only appear once you deliver its life gem to its door. Unlike the traditional shrines in the game, you must follow the green light to retrieve the crystal and use it to enter the shrine.
En-Oma Shrine is a blessing shrine and merely entering the Shrine will make you worthy of the blessing. However, you must complete the Shrine Quest related to the Green Crystal to enter it. In this guide, we will discuss where to find the En-Oma Shrine and how to complete its shrine quest in Zelda: TotK.
En-Oma Shrine Location in Zelda: TotK

En-Oma Shrine (0104, -2517, -0087) is in a Whirlpool Cave in the middle of Lake Hylia. This Whirlpool Cave is in the South of Hyrule Field, East of Hylia Island, and West of Popla Foothills Skyview Tower (0603, -2123, 0098).

You must complete the Lake Hylia Shrine Crystal quest to enter this shrine in Tears of the Kingdom. However, the first step is to find the Shrine. You can enter the Lake Hylia Whirlpool Cave by diving into the Whirlpool that you can see below by using the Popla Foothills Skyview Tower.
The Lake Hylia Crytal Quest Walkthrough

Interact with the shrine to start the shrine quest “The Lake Hylia Crystal“. The Shrine Crystal is on one of the Islands in the Sky, right above the Whirlpool. Now what you have to do is Travel to the Popla Foothills Skyview Tower and start going southwest toward the Island above the Whirlpool.

Gliding all the way will require ½ wheels of Stamina with Tulin’s Gust of Wind. Once you reach the Island on the Faron Sky Archipelago, grab the Shrine crystal from a temple and throw it down from the hole in the Island. Jump after the Shrine Crystal. You both will automatically get into the Whirlpool and ultimately inside the Whirlpool Cave in Zelda TotK.

Take the Shrine Crystal to the Shrine and a short cutscene will start and after that you can enter the En-Oma Shrine in Zelda Tears of the Kingdom.

En-Oma is a blessing Shrine, you just have to enter it, collect the rewards and follow up with your conquest. The Shrine Chest contains a Mighty Zonite Sword, and the second reward is the Light of Blessing.
You can exchange the Light of Blessing at the Goddess Statue for a Heart Container or Stamina Vessel in Legend of Zelda: Tears of The Kingdom