follow these steps:
- From your Blogger dashboard, go to "Template") "Edit HTML"
- It is always recommended to backup your template before you make any changes in your code. click "Backup/Restore", then click "Download full template".
- Add the code below after the <head> tag.
<b:if cond='data:blog.pageType == "archive"'>To make sure that the tag is been added successfully on your pages, go to an archive page and open the source code. Check if you find the following code:
<meta content='noindex' name='robots'/>
</b:if>
<meta content='noindex' name='robots'/>