[Plugin: Custom Field Template] Type text, date = true with multiple button don't work

I have created with this plugin new teplate:

[Multiple fields date]
type = text
size = 35
label = One date of ...
date = true
singleList = true
multipleButton = true
multiple = true

…but link of multipleButton isn’t active

I have tryed change type from text to textfield but don’t work.

My idea is to add new fields associated with the calendar.

https://www.ads-software.com/extend/plugins/custom-field-template/