Publish addon in mozilla AMO

[alireza-ansaripour]

I've just used kango to create an extension and I want to publish that extension in https://addons.mozilla.org. But when I upload the .xpi file, I get the error Starting with Firefox 53, new extensions on this site can only be WebExtensions. . How to create a WebExtension in kango

[Ododo]

As explained in this page
Chrome extensions can be loaded in Firefox latest versions (using the WebExtensions API)
So try to load the manifest.json in the chrome output of Kango and see if it works.
Of course it is a temporary fix but it works for me (I have a single-popup app)
Maybe a few changes will be required

[OlivierBonjour]

I also successfully used the chrome output for firefox, you have to adapt the manifest a little bit but it works. Anyway, this project seems to be dead so I don't suggest using Kango if your starting a new extension.