The Ja Baij Shrine contains the Bomb Trial, where you get new runes for your Sheikah Slate.
How to Use the Remote Bomb Rune
Check on the pedestal to get the Remote Bomb Rune added to your slate. Press and hold up on the directional pad if you want to switch the rune that you are currently using.
When you choose a remote bomb rune, you can take out a remote bomb by pressing L. You can set it down with A or throw it with R. If you are holding the bomb, you can press B if you want to put it away (this also works if you pick up a bomb that you put down before). After you put the bomb somewhere, run away from it, then press L to detonate it. If pressing L doesn't work, make sure that your Sheikah Slate is set to the correct bomb rune. The bomb rune will be flashing if you have placed a bomb of that type somewhere.
Use cube-shaped remote bombs when you don't want the bomb to roll away. Use round ones if you want the bomb to roll.
Reach Ja Baij
Use a remote bomb to blow up the cracked stone cubes in the wall. Go through the new opening. There are two sets of cracked blocks in this area. Blow up both. Beyond one set of blocks, there is a treasure chest that contains a Traveler's Claymore.
The other path leads to a ladder. Go up, then switch to the cube bomb rune, and put the bomb onto the moving platform, but don't ride the platform yourself. Detonate the bomb when it is near the cracked blocks. Then ride the platform across.
Then turn left and you will see Ja Baij in the distance. There is a treasure chest to the left. Go toward the chest, then climb up to the stone launcher. Let it launch you to the treasure chest. Open it to get some Amber, which you can sell later or keep for other purposes.
Then go toward the stone launcher on the other side of the room. At the top of the stairs, put a round remote bomb into the funnel. Wait for the bomb to be launched to the far side, then press L to detonate it.
Then go to the lower area and climb up the ladder to where the cracked blocks were. From there, you can check on Ja Baij to get a Spirit Orb and complete the trial.