Captcha Problem

I want to add captcha on my wp-login page but there is a conflict with pie register. If i install other plugin for wp-login captcha the pie register is not working. Even if the user solves the pie register captcha there is still an error. Seems like the captcha is running twice but not visible.

How i can solve this problem? Is very important because bots keep hitting wp-login.

https://wordpress.org/plugins/pie-register/