1. Identify the duplicate pages. The first step is to identify the duplicate pages on your website. You can use Google Search Console to do this. In Search Console, go to Coverage>Errors and look for the Duplicate error. This will show you a list of all the pages on your site that Google has identified as duplicate.
2. Choose a canonical URL. Once you have identified the duplicate pages, you need to choose a canonical URL for each page. The canonical URL is the one that you want Google to index and show in search results. You can choose the canonical URL based on the following factors:
   • The most important page. If you have two pages that are essentially the same, choose the one that is most important to your website.

• The page with the most content. If the two pages have different content, choose the page with the most content.
• The page with the most backlinks. If the two pages have the same content, choose the page with the most backlinks.

1. Add canonical tags. Once you have chosen a canonical URL for each page, you need to add canonical tags to the pages. Canonical tags are HTML code that tells search engines which URL is the canonical version of a page. You can add canonical tags to your pages by editing the HTML code of the pages.
2. Add 301 redirects. In addition to adding canonical tags, you can also add 301 redirects to the duplicate pages. 301 redirects tell search engines to permanently redirect traffic from one URL to another. This is a good way to ensure that all traffic for a duplicate page is directed to the canonical URL.
3. Check your sitemap. Make sure that your sitemap is updated to reflect the changes you have made to your canonical URLs. You can use Google Search Console to submit your sitemap to Google.

By following these tips, you can fix duplicate canonical problem and ensure that your website is indexed correctly by search engines.

Here are some additional tips:

• Use the same title and meta description for all duplicate pages.
• Link to the canonical URL from all duplicate pages.
• Make sure that the duplicate pages have different content.
• Use a canonical tag on the canonical page itself.

If you have a lot of duplicate pages, it may be helpful to use a canonicalization plugin for your CMS. These plugins can help you automatically add canonical tags to your pages and manage your canonical URLs.