In this example, Google will likely choose the canonical URL for indexing and ranking. The canonical page is also called the “principal,” “primary,” or “representative” version. A canonical tag, also known as rel="canonical" tag, is a snippet of HTML code that allows you to define the “primary” version in a set of duplicate or near-duplicate pages on your site.
How to Set Canonical Link for Blog
Go to "Sites" > "Blogs"
Edit the Blog by clicking the name of blog with the button of Edit Blog Site
When you publish the content of Blog, it shows in canonical links.
How to Set Canonical Link for Blog Post
Go to "Sites" > "Blogs"
Go the blog name and click on it
In the blog, there will be blog posts created for content distribution.
Once the blog post is content is ready, if you click on "Continue".
The blog post allows you to set canonical link.