limit-submission-time.php

<?php

add_filter( 'forminator_custom_form_submit_errors', function( $submit_errors, $form_id, $field_data_array ) {
    // Add your form IDs here.
    $form_ids = array( 842 );
    // Change this to the message that you want to show.
    $message = 'You cannot submit more than 5 times within 30 days.';
    if ( in_array( intval( $form_id ), $form_ids, true ) ) {

        $user_ip = Forminator_Geo::get_user_ip();
        if ( ! empty( $user_ip ) ) {
            $last_entry = wpmudev_get_last_few_entries( $form_id, $user_ip );
            if ( ! empty( $last_entry ) ) {
                $entry = Forminator_API::get_entry( $form_id, $last_entry );
                $current_time = strtotime( date( 'Y-m-d H:i:s' ) );
                $future_time = strtotime( '+2 minutes', strtotime( $entry->date_created_sql ) );
                
                if ( $current_time < $future_time ) {
                    $submit_errors[]['submit'] = $message;
                }
            }
        }
    }
    return $submit_errors;
},15,3);

function wpmudev_get_last_few_entries( $form_id, $user_ip ){
    global $wpdb;
    $table_name       = Forminator_Database_Tables::get_table_name( Forminator_Database_Tables::FORM_ENTRY_META );
    $entry_table_name = Forminator_Database_Tables::get_table_name( Forminator_Database_Tables::FORM_ENTRY );
    $sql              = "SELECT m.`entry_id` FROM {$table_name} m LEFT JOIN {$entry_table_name} e ON(e.`entry_id` = m.`entry_id`) WHERE e.`form_id` = %d AND m.`meta_key` = %s AND m.`meta_value` = %s order by m.`meta_id` desc limit 4,5";
    $entry_id         = $wpdb->get_var( $wpdb->prepare( $sql, $form_id, '_forminator_user_ip', $user_ip ) ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
  
    if ( $entry_id ) {
        return $entry_id;
    }
    return false;
}