We are working hard on the platform upgrades at the moment and plugin for Wix in not planned in foreseeable future.
Embedding iFrame to Wix is straight forward and works fine. However, you need direct embedding for access to the ShapeDiver API, see code example below, for more check our CodePen library. We don’t have any experience with the Wix API so I can’t give you any advice but I’m sure a good web developer will be able to help. The documentation with the API reference is good point to start.