After the extension is imported (downloaded via the github link mentioned by TIMAI2), in block I can see it. when click on it, it asks me to always use MS to open it. after i closed the dialogue box, the extension disappears from the left panel. I imported it again, nothing shows up on the left panel. How can we use this extension? Thanks.
The reason why it might be asking for you to open it in Word is that you have Auto-Open after Download, which prompts the computer to search for an application so it can open the .aix file.
Also, try clicking "OK," instead of "Close."
I tried it now, and it appears to be normal now after some 5-6 hours.