display action

add_action( 'ninja_forms_display_init', 'my_filter_functiontwo', 10 );

function my_filter_functiontwo( $form_id )
{
    global $ninja_forms_loading;
    if ( 66 == $form_id ) {
        $user_info = get_userdata(1);

        //Grab the user's first name and update the value of field 1098. 
        $ninja_forms_loading->update_field_value( 1098, $user_info->first_name );
    }
}