You'll have to do more than just 9.2 downgrading
But to answer your question, yes you can. Just follow the guide and you'll be fine.
https://3ds.guide/nfirm-downgrade
Be warned tho, you need one of these four games:
- Fieldrunners
- Legends of Exidia
- Guitar Rock Tour
- The Legend of Zelda: Four Swords (Anniversary Edition)
IIRC, they've been pulled so if you never got them you're pretty screwed. There was talk about you being able to use almost ANY Dsiware title instead of the 4, but I don't know too much about it.