Should we use login captcha plugin?

What problem are you trying to solve with it?

Can you please let us know exactly which plugin you are referring to?

There is no plugin i just ask is that important or not?

Login security is super important. Strong password is the first step. Beyond that – kinda up to you what measures you take. Limit Login Attempts Reloaded is widely recommended. WPS Hide Login has its fans and detractors, I am among the former. A login captcha or recaptcha plugin adds another layer of security with just a bit of inconvenience so very much worth considering, though I prefer using CloudFlare page rules to accomplish basically the same thing – keep bad login bots at bay.

No, a captcha is not important on login. I use WordFence to keep an eye on logins.