get_user_info filter?

i’m trying to get this to work.
i want to basically remove parts of the admin email sent out. i am aware there is no easy way to customize this.
i was trying to use add_filter to customize this, but the following is not working. what am i doing wrong?

add_filter(‘class-fscf-process’, ‘strtest’);
function strtest() {
$string1x1 = “$user_info_string .= __( ‘From a WordPress user’, ‘si-contact-form’ ) . ‘: ‘ . $current_user->user_login . self::$php_eol;”;
echo str_replace($string1x1,”,$string1x1);

}

https://ww.wp.xz.cn/plugins/si-contact-form/