Can you please upload the extension to Firefox addons too. This extension is perfectly compatible with Firefox and I tested the crx at [extensiontest.com](https://www.extensiontest.com/) and it was compatible. So by following this guide [https://extensionworkshop.com/documentation/develop/porting-a-google-chrome-extension/](https://extensionworkshop.com/documentation/develop/porting-a-google-chrome-extension/) and by using [web-ext](https://extensionworkshop.com/documentation/develop/getting-started-with-web-ext/#testing-out-an-extension) tool I signed the zip provided in the release page and uploaded the xpi file generated by the tool in Firefox and it is working without any issues. So, I think you can upload your extension to Firefox with zero changes to your code.