According to https://docs.telerik.com/kendo-ui/controls/data-management/filemanager/context-menu:
You can define your custom items which can execute custom commands
However, no option allows me to configure my own commands.
I managed to hack this: https://dojo.telerik.com/@GaloisGirl/iLoHIhoh , but it's an ugly solution.
Reproduction:
As can be seen on the screenshot on https://www.telerik.com/support/whats-new/kendo-ui :