In Genshin Impact, Stella Fortuna varies character to character. The item can be used to activate the Constellations of the character in question. Stella Fortunas are exceedingly rare, but they can be be earned reliably by following certain steps. Here's how to get a Stella Fortuna for yourself.
Genshin Impact Stella Fortuna: How to Get Stella Fortuna
There are three ways to unlock Stella Fortuna as the main character. Progressing the story, buying in the Souvenir Shop and completing Adventure Ranks for their rewards can all be avenues to receiving Stella Fortunas.
For characters other than the main character, the only way to obtain Stella Fortuna is through wishes. Each wish provides a chance for players to receive a new character. Once you have enough characters unlocked, you'll occasionally receive duplicate characters through wishes. Whenever you would receive a duplicate character, the wish will instead produce a Masterless Starglitter and a Stella Fortuna for that character.