At Audacity ® | | Download for Linux I read the following:
Audacity does not run on Chrome OS. Although not officially supported, it is possible in principle to run Audacity on a Chromebook under a > Chrome version of Linux Ubuntu.
And at the linked page
I read similar, well I have great news.
Chromebooks released from 2018 and on all have built in Linux and support Debian package.
Including installing Audacity - and it works!
For some Chromebooks the hardware acceleration of the video card is not yet perfect, so the icons of Audacity can show up as black squares, this can be fixed by https://community.smarttech.com/s/article/Turning-off-hardware-acceleration-on-Chromebooks-to-improve-screen-sharing?language=en_US and after that it all just works.
For now I only see the 2.2.2 Debian Package, and I love to try 2.4 of when the debian package is released.
P.S. For people with chromebooks who can’t find linux; How to install Linux apps on your Chromebook | Android Central how you could enable Debia Stretch, recently the ChromeOS UI did change a bit for configuring, but itś still about enabling Crostini Linux (Beta) - but it just works fine.
Then on the Linux comand line run
sudo apt install audacity
and after a few moments you’ll have the Audacity icon available like you have your other apps available in ChromeOS.