I have a blog: http://blog.example.com from blogger.com.
I have a few articles there.
I also have a blog on my website http://www.example.com/blog on WordPress.
I have the same articles (that I have on Blogger) here.
This means I have duplicate content and to avoid to be penalized by Google I understood I need to add the rel=canonical tag.
However, I would like to keep both blogs (Blogger and WordPress), and since I would like to push the views of my website I would like to set my preferred URL to http://www.example.com/blog.
So I would like to add the following tags to Blogger:
<link rel="canonical" href="http://www.example.com/blog/article1"> etc.
I have difficulties to add the tag to Blogger, how do I do it?
Well, you would have to add the canonical-tag to your site header section. Most hosted blog-systems like wordpress.com or blogger will not allow you to edit the theme files (and therefore output the mentioned tag).
If editing the theme output or changing the functions.php is not possible, you are not able to set that tag, I think. Sorry.
You can edit your Blogger theme via Customizer to add conditional tags that would inject rel=canonical tag matching each blog post’s permalink.