Hi Marina,
actually the course is based on 9.12.4 and and the latest version of mendix has been updated and the create button has been shifted to open page button. on the open page button, there is an option of create object.
Also, if you want to get the full functionality of mendix, just like the rapid developer course, try downloading the Mendix version 9.12.4. and switch to studio pro.
This way you’ll get what you see.
Hope it helps!