Duplicate without user-selected canonical” means that Google has detected multiple pages on your website that have similar or identical content, but it has not been able to determine which page should be considered the “canonical” (preferred) version. This can be a problem because it can lead to confusion for search engines and can dilute the ranking power of your website.
To resolve this issue, you should identify the pages that have similar or identical content and decide which page you want to be the canonical version. You can then use the rel=canonical link element to indicate to Google which page you consider to be the preferred version. This will help Google to understand which page to index and rank, and will prevent any potential issues with duplicate content.
To use the rel=canonical link element, you need to add a link element to the head section of each page that has a duplicate or similar version. The rel=canonical link element should point to the preferred (canonical) version of the page.
For example, let’s say you have two pages on your website, page1.html and page2.html, and you want page1.html to be the canonical version. To specify this, you would add the following link element to the head section of page2.html:
<link rel="canonical" href="https://www.example.com/page1.html">
This tells search engines that page1.html is the preferred version of the page, and that they should index and rank page1.html instead of page2.html.
It’s important to note that the rel=canonical link element is just a hint to search engines, and they may choose to ignore it if they believe that a different page is more relevant for a particular search query. However, using the rel=canonical link element can help to improve the clarity and organization of your website, and it can help to prevent issues with duplicate content.