WebChat.close() does not work

[zusibell]

I want to be able to ask for feedback before the chat window closes.

onWidgetEvent: {
                onChatClose: function() {
                    WebChat.send("/feedback")
                    WebChat.close()
                }
            }

the request /feedback gets send but the chat doesn't close after that. Do I need to have something else? Even if I left the WebChat.send away and leave only the WebChat.close() the chat window won't close on click.

The error I get in the console is the following:

index.min.js:129 Uncaught Error: Reducers may not dispatch actions.
    at p (index.min.js:129)
    at Object.dispatch (index.min.js:129)
    at Module.ui (index.min.js:129)
    at Object.onChatClose (home:46)
    at index.min.js:129
    at index.min.js:129
    at p (index.min.js:129)
    at index.min.js:129
    at s.value (index.min.js:129)
    at toggleChat (index.min.js:129)

I am using the <script> tag in an angular project.
How can i resolve this?