I found these undecuplets (11-tuplets) and duovigenuplets (22-tuplets) in Chopin's Nocturne in B-flat minor, Opus 9, Number 1:
I want to use such tuplets in my own music. How can I write them in Noteflight?
Noteflight doesn't offer anything more than septuplets. There are several requests for more in the Noteflight feedback forum.
A work-around would be to split the tuplet up. Probably almost nobody can accurately play 22 notes over a whole measure.