If you have Geogebra content uploaded, there should be a Embed button in the teacher page.
This produces code that will embed the Geogebra content into Mobius. To use it, create a new question/text and then click on the "Source" button. This will open the HTML code for the question. There you can paste the Embed HTML code from Geogebra and when you preview the question, the Geogebra content will appear.