On top of upgrading your characters the Sea Ganoderma are often used in Genshin Impact, while not that hard to find you'll still need a lot of them so here's a guide to where you can get your hands on a bunch.
Sea Ganoderma Location in genshin Impact
The Sea Ganoderma can be found pretty much everywhere in Inazuma.
If you're looking for a more precise location for all these Onikabuto I'd advice checking the official interactive map where you'll be able to zoon as you see fit.
You can find the map on the Hoyolab website here.
