Math Captcha doesn't work

The problem with displaying math captcha on contact form 7 is solved by inserting shortcode [mathcaptcha mathe] in template of contact form.
But math captcha isn’t displayed on registration form. I use theme my login plugin for registration and authorization. Are there any idea how to display mc on registration form?

I solved the problem.
The problem was in class-core.php. For registration and lost password wasn’t carried out сonditions: $action === ‘register’ and $action === ‘lostpassword’.
I use new variable $page = $_SERVER[‘REQUEST_URI’] and new conditions:
$page === ‘/register’ and ‘/lostpassword’

Thanks for posting! This was helpful for me to get math captcha working on my bbpress registration page. I had to change my values slightly to match the names of my pages. (i.e. $page === ‘/registration-form/’ instead of $page === ‘/register/’