flyctl launch -a docs out of date?

I was reading the docs and came across this:

Whenever flyctl is run, it will look for a fly.toml file in the current directory and use the application name in that file. This behavior can be overridden by using the -a flag to set the application name, or on some commands (such as deploy) by using a -c flag to point to a different fly.toml file.

However, when I pass -a or --app to flyctl launch, it says that it’s unrecognized.

Ideally, I’m trying to create a prod/non-prod application deployment that uses identical fly.toml files. This seems like how I would do it in theory.

For info, there was a similar post about the CLI doing such a thing.

I’d guess a bug in flyctl…

Looks like this only works on deploy and assumes you launched the app with an initial fly.toml. But the docs confused me at first.