How to get the drawing canvas as a Base64 string?

Hi! We are using the Drawing Canvas object to compose an image that we then want to send as a custom update to facebook instant game. For this we would need the contents of the Drawing Canvas as a base64-string. (The equivalent of toDataUrl() on a canvas DOM object). Is this possible in any way? We tried with the SavedImageURL property set by the saveImage action but it seems to be only a URL and not a base64 string

Thanks!

We also tried choosing the Drawing Canvas directly when selecting an Image to send with the Facebook Instant custom update, but it didn't work. That would have been great though

Thank you Eren! We tried your plugin and it works perfectly. You made our day :)