captcha on client login page ?

How can we add a capatcha to the client secure login area page ? – I added a Google Captcha plugin but it did not show up on this client dashboard page — as a matter of fact, the login stopped working on that page as it was not showing the captcha box but it still was expecting it to be filled in. Its when I deleted the plugin it started to work again

J

https://ww.wp.xz.cn/plugins/sliced-invoices/