1-liner process substitution for ksh

I have this command, which works fine for bash: sh <(curl -sSl https://appi.sh/launch) (launches [this interactive script](https://github.com/Appish/appi.sh/blob/master/launch.sh)) I'd like to get this 1-liner working for ksh, too. Currently, it errors with:

syntax error: (' unexpected

Running the script from ksh as sh launch.sh works fine, so I'm hoping there's a way to have a singular 1-liner that will work in both bash/ksh without exponentially increasing the length of the command.