client-ip-jfb.php

<?php

add_filter(
            'jet-form-builder/send-email/message_content',
            
            function ( string $content ) {
                        
                        return str_replace( 

                                    '%client_ip%', 

                                    \Jet_Form_Builder\Classes\Http\Http_Tools::get_ip_address(), 

                                    $content 

                        );

            }

);