Duplicate a post created with Formidable Forms frontend post submission, so that it is available in all languages. Needs WPML.

wpml-formidable-duplicate-post-langs.php

<?php
add_action('frm_after_create_entry', 'add_translation', 30, 2);

function add_translation($entry_id, $form_id) {
    
    $forms = array( 64 ); // <---- change or add form ids here, comma separated, e.g. (24, 53, 64)
    
    // check if form id is in array, if so run code
    if( in_array($form_id, $forms) ) { 
        
        // 1. get the post_id of the CTP post just created
        $post_id = FrmDb::get_var( 'frm_items', array( 'id' => $entry_id ), 'post_id' );
        
        // 2. Make a duplicate of the post in all languages
        global $sitepress;
        do_action( 'wpml_make_post_duplicates', $post_id);
    }
}
?>