You probably want to make your own.
The main requirements are that the button have 1) the 'add_element' class, 2) a 'data-rep-id' attribute that contains the id of the repeatable to which you want to add an element.
has_field 'add_element' => ( type => 'AddElement', repeatable => 'foo', value => 'Add another foo', );
Requires the name of a Repeatable sibling field.
The value of the button that's rendered, 'Add Element' by default.
FormHandler Contributors - see HTML::FormHandler
COPYRIGHT AND LICENSE
This software is copyright (c) 2016 by Gerda Shank.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.