How can I fix 404 pages?

Hello, I installed your plugin in the WordPress system, but there is a 404 error like this:
https://www.ukocarbide.com/author/carolyn/reputations/
404
https://www.ukocarbide.com/author/emmo/reputations/
404
https://www.ukocarbide.com/author/glorie/reputations/
404
How can I fix it? Thank you!