Printer selection can happen one of two ways. by either selecting a printer from the list or by using the dynamic printer name.
Printers can only be selected from the list if " Use dynamic printer name" is disabled.
Using dynamic printer name works by writing the start of the printer name, and when the report action is executed it will look for a printer the start with the same name.
Usage of dynamic printer names will only work if only one printer matches the name.