Looking at the documentation we are seeing that the crossbrowsertesting tool support various Operating systems and thus corresponding browsers as mentioned in the below link
https://crossbrow...
Currently, you cannot use TestComplete to test on MacOS and Ubuntu OS.
The CrossBrowserTesting tool, directly, has the ability for doing some automation of browsers and such on the various environments. You will probably benefit from engaging in the CrossBrowserTesting forum and documentation on how to do so.