ACF Pro 5.9 comes with a duplicate row feature on its own. The “ACF Duplicate Repeater” plugin is no longer maintained.
Duplicate Repeater and Layout Fields in ACF Pro.
Supports all ACF Native fields.
Development
Please head over to the source code on Github.
If you are looking for support on Non-ACF-Fields, there is some documentation in the wiki, that might come in handy.