First open the template settings [Template configuration] using
-> The Media Editor [Media editor] opens.
Select the type in the list field top right. The following options are available:
-> In the lower half of the dialog box the already existing Media Variables of the selected type are displayed.
In the list field top right, you can select a language. For a variable's new creation leave "default".
The variable is displayed in the lower half of the dialog box.
Select the variable and enter the variable value in the upper half of the dialog box.