Cascading lookup fields

In Youtube exist learning
about cascading lookup fields.
We couldn't find element Form with these options like in the presentation. Please give the advice how we could realize the feature in the new Version og Radzen?

This video is for Radzen Angular applications. You can check this forum thread which shows how to implement that in Radzen.

Is the possibility to use TextBox element instead of the first element list (Customer list - from example of documentation), and second like in example (list datadropdown)? TextBox has only value property , but has not the data property .

Indeed a textbox does not have a Data property nor will it ever have. It is meant for text entry.