Uninstall addon from site using REST

I have one instance, where for some reason application doesn’t have “Uninstall” button. (In other sites all is fine)
How to uninstall addon using REST API?
I’ve tried to do this with Postman 'DELETE', using '/rest/atlassian-connect/1/addons/{addonKey}' but with no result. It only returns description of the installed plugin.
Any idea?

I haven’t tried it myself as atlassian-connect-express will register/unregister automaticly if you provide a credentials.json but looking into their code they seems to call the following URL with a DELETE

If you have a token for the plugin, you may need to remove the token first.