Usually you install an apk file on yout test device to test it. .
Please download the test project to avoid new errors... the example project is tested and is working... please confirm and after that we can go to step 2
Ok, my guess is you are talking about the apk file here.
Please download the example project (aia file) from the download section here App Inventor Extensions: Textbox | Pura Vida Apps, import it into App Inventor and test it using the companion app
@nathaniek2011 can you use a real device with companion app? It will work there.
This issue is not confined to chromebooks and the companion app installed on it, but also can affect other emulators (e.g. genymotion) that disable the on screen keyboard.
@nathaniek2011@TIMAI2 thank you for your tests. I will add a note in the documentation, that the text changed listener as well as the enter pressed listener does not work in emulators and Chromebook using companion app because of the absense of a on screen keyboard