Hi,
This was already requested and you can Follow its status in the following page: https://feedback.telerik.com/blazor/1416922-add-to-teleriktextbox-more-parameters-such-as-type-autocomplete-required-readonly. It also shows a workaround through the k-textbox class. I see you have already voted for it and I am now closing this one as a duplicate.
Regards,
Marin Bratanov
Progress Telerik