This item will be available in R1 2021 SP1 Release.
It is also available with Telerik UI for WPF's latest internal build - LIB 2021.1.215 (15/2/2021)) if you need it earlier.
Regards,
Peshito
Progress Telerik
Virtual Classroom, the free self-paced technical training that gets you up to speed with Telerik and Kendo UI products quickly just got a fresh new look + new and improved content including a brand new Blazor course! Check it out at https://learn.telerik.com/.