Troubleshooting duplicate content boils down to one definition: specifying which of the duplicates is the “correct” one. Whenever a site’s content can be found on multiple URLs, it should be canonicalized to search engines. How? With a 301 redirect to the correct URL, the rel=canonical attribute, or by using the parameter manager in Google Search Console.
301 Redirect
In many cases, the best way to combat duplicate content is to set up a 301 redirect from the “duplicate” page to the original content page. When multiple by lists pages with the potential to rank well are combined into a single page, they not only stop competing with each other; they also create a greater overall relevance and popularity signal. This will positively impact the “correct” page’s ability to rank well.
rel = "canonical"
Another option for dealing with duplicate content is to use the rel=canonical attribute. It tells search engines that a given page should be treated as if it were a copy of a given URL, and all links, content metrics, and “ranking power” that search engines apply to this page should actually be credited to the URL.