If you want to access a training course or demo content located on another Mission Center than your own, then you need to ask for a user license as follows.
Next click on Acquired Licenses (if the menu is not displayed, see here) then on Request license.
Fill in the pop-up window and finish by clicking on Request license.
The supplier then receives an email that allows him to generate the license.
Note: this operation is only necessary in the case of a new supplier. Once registered in the Mission Center, there is no need to renew your request.