Some — though not all — Chrome OS devices support Android apps. All new ones made in 2017 and beyond do, and some legacy Chromebooks do as well. As a result, there are millions of Chrome OS devices that have access to your app.
Some of those devices do not have touchscreens. Your app will need to declare that it supports non-touchscreen devices in the manifest.
Chrome OS devices that do have touchscreens will be able to install your Play Store app, even if you have not specifically opted into Chrome OS support.
If the Chrome OS market is strategic to you, you should plan to invest in a few Chrome OS devices and do your own compatibility testing.
However, it may be that you just want to ensure that your app will work acceptably on Chrome OS, without investing a lot of engineering time trying to determine what does and does not work. Here, CommonsWare can help you, testing your app on touchscreen (and, if appropriate, non-touchscreen) Chrome OS devices. You will receive a report outlining what works and what does not, so you know where to focus your efforts and if Chrome OS support makes sense overall. For cases where CommonsWare can reproduce your app's problems independently, CommonsWare will file issues with the Chrome OS team as appropriate.
Interested? Contact Mark Murphy to discuss what you need (touchscreen? non-touchscreen? manual testing? running your existing test suite?) and to get a quote for the work.