Dialog API set values of dialog fields based on other fields?

Using the Dialog API, how do I set the value of a field within the dialog based on another field in the dialog?

For example, if the user selects “Foo” from a select Field, how do I insert “Bar” into the text Field?

Basically, I need a method to capture the dialog form change events, and one to set the values of the fields.

Hy @oguruma

If you want to set onchange trigger value you should see this post

Thank you!