Recover software VTOL software

Hello, i’m looking for recover the Firefly software to modify him to apply it on my own VTOL (Study project).

Where can I recover the source code? I can’t find it on the git.

Thanks for your help.
RABBE Xavier

What do you mean by recover? I don’t think Firefly support was ever removed.

I would like to have the source code of firefly in order to made my own modification on the source code.
Is it more explicit?

Thanks for your help.

The Firefly is an airframe, not a separate flight stack, The flight stack is PX4 and you can find the source code here: