Before presenting these different methods, a small clarification. An exercise will only be really effective if you use the online version of GeoGebra: on the desktop version, it is not possible to prevent access to the “Algebra” window which contains all the objects created. Even if this window can be closed, it is still very easily accessible and opening it would allow the reading and display of all the objects and therefore of those that you want to hide.
It is therefore necessary to create a GeoGebra account (free) on the website https://www.geogebra.org/
The file can be created either directly in the online activity editor or on the desktop version of GeoGebra. In this case, the file must be uploaded to the GeoGebra online resources.