Not Working with WordPress version 4.9.2?

and it does not display on the login

Of course not. Read the plugin page to learn how to use the plugin.

so its not working with 4.9.2… only compatible with 4.8.2 – the button “captcha” in the backend (forms) its not available.
so we all need to switch to recaptcha plugin? and leave your work ???

after some search i found this one:
https://contactform7.com/captcha/

Not everyone wants to use Google products as they’re making so many processes so difficult.

And why be snarky and rude about your own product when people still want to use it (“Of course not. Read the plugin page to learn how to use the plugin”)?