Making a form field visible when a dropdown select is of a certain value

I put a select field in a form with text values as choices in the table with one of the choices being “Other”.
I have another field which I’d like to have appear when a user selects “Other” in the select field.
I tried a dynamic attribute of show to the value of the select field. That doesn’t seem to work for me. Is that the right way to do this?

Thanks,
Rick