In order to include Magento 2 Blog link in the top navigation menu:
1. Go to the Stores > Configuration > Magefan Extensions > Blog and find Category Top Navigation section.
2. In the Display Blog Link select box choose whether to display a blog link in the menu or not.
3. In the Link Text indicate the text of the link which will be displayed on the storefront.
4. Select whether to include blog categories in the Include Blog Categories field.
. Enter the maximal amount of subcategory layers to be displayed in the category top navigation in the Maximal Depth field.
Once you fill in all the fields, don't forget to press the Save Config button and then configure the blog route in blog permalink settings.
If you configured the blog category top navigation, but the blog link doesn't appear in the menu you might have custom theme.