Hi, I have encountered a similar situation myself.
What I ended up doing was using the LibGDX setup tool to create a project with identical settings (package name, game class, etc.) to what my original project was, and making sure the ios-moe box was checked. I then copied the ios-moe folder over to my old project and added ios-moe as a build target in the projects settings.gradle file.
It's worth noting that my original project was setup with the same libgdx version as the one I used to generate the ios-moe module. I would suggest updating your project before trying this method. This method may have some side effects that I am not aware of, although its worked for me with no issues so far.
I would also be interested in a more proper solution if one exists or any potential issues this method may cause.
Hope this helps,