4XX Page Description & How to Fix
4xx HTTP status codes indicate that the requested page or resource cannot be accessed. 401 - Unauthorized, 403 - Forbidden, 408 - Request Timeout, and 404 - Not Found are the most common "Client Errors".
4xx URLs damage the user experience on your website as people cannot access the page or file via a link they click. Besides, internal links to 4xx URLs create unnecessary "dead ends" for the search engine crawlers and can waste your crawl budget.
How to fix
You should review the internal outgoing links to all the 4xx pages reported and either remove these links or replace them with relevant links to live pages.
Alternatively, you can set the appropriate 301 redirects. It is especially important when for moved or deleted pages on your website.
This will provide smooth crawlability for your website and guarantee good user experience.