WordPress Redirect 301 register page

I have a custom register form page, and I want to create a 301 redirect to force people to use this form (and not the original URL of WordPress)

I try to do a redirect 301 like this in my .htaccess, but it doesn’t work.

Redirect 301 /wp-login.php?action=register https://monsite.com/register/

What’s wrong here?

I would advice you to not use the htaccess for this, but to use a WordPress hook instead.

Check out https://developer.wordpress.org/reference/hooks/login_url/