did not find s special place for TTG BE admin related questions ...
In TTG BE Settings I find the option to define a template in the personalization section. In the corresponding prompt list no entries are available to choose from. Do not know why.
Also in case that there would be a template to chosse from I would not know what this template I really good for.
The help text corresponds to the appearance of customer facing cart pages. That's confusing because exactly this should be done in the admin cart settings dialogue (personalization)