Sorry, but I gotta ask cause I am confused now. I have seen your axetale where Frisk died giving birth to her daughter, but I have seen other au called Axetale where Frisk is still alive in the outside world she is just stuck and tortured in an mental institution. Which one is the canon for Axetale or are they both different au possibilities? Thank you.

Both are canon. Frisk lived in a mental institution for a time on the surface, driven mad by the drugs she was given there, before being freed into her mother’s care. She died after that, after giving birth to Aliza.