To get to Inazuma, you need to finish the quest “Chapter II: Prologue – Autumn Winds, Scarlet Leaves” (kazuha’s quest) to unlock the quest needed to go to Inazuma (with ayaka).
Don’t even try ice bridging there with Kaeya because once you reach a certain point you will get struck by lightning and teleported back to Liyue. So unless you want to get the achievement. I don’t recommend doing that.
Feel free to ask me any more questions 🙂