As written here:
The Model Target tracker uses a loaded dataset to recognize and track objects. This dataset is created using the Model Target Generator and online Target Manager tool.
If I open Target Manager, I can create these types of Databases: Device, Cloud, VuMark. If I choose Device, I can add one of these Targets: Single Image, Cuboid, Cylinder and 3D Object.
Where can I add Model Targets?
I don't know why they said that but you don't need to use the Target Manager, only the License Manager (to get a new license for your project).
PS: with the Model Target Generator you will have to connect to your Vuforia account.
Pierre