It’s not really possible with ACF without doing an quite a bit of work. I suppose you could create a true false field called “dulicated” or something like that, then create a pre_save_post filter and test if that field is checked. If it is then create a new post by copying the values and returning the new post ID from your filter.
This is the plugin I use for duplicating posts, but it does not work on the front end. https://wordpress.org/plugins/duplicate-post/
