If you have enabled related posts on your Blog posts, you might have noticed that the Related Posts Title has the <h2> heading tag assigned by default.
You can modify this tag to any other HTML tag by adding a filter to the functions.php file of your Astra Child Theme. If you don’t have a Child Theme installed and activated on your website, please check this article on how to do this.
How Can I Do This?
You can use the filter below to change the tag for the Related Posts Title to any other tag. Please follow these steps:
Step 1 – Navigate to Dashboard > Appearance > Theme Editor and select the Child Theme;
Step 2 – Add the filter below to the functions.php file of your Child Theme. You can check this article on adding code to your Child Theme to help you out;
// Filter for changing related posts title heading tag.
add_filter( 'astra_related_posts_title', 'update_related_posts_title_markup', 10, 1 );
function update_related_posts_title_markup( $markup ) {
    $markup = '<div class="ast-related-posts-title-section">';
     $markup .= '<h4 class="ast-related-posts-title">'; // Replace H4 with the tag you need.
 $markup .= 'Related Posts';
 $markup .= '</h4>'; // Replace H4 with the tag you need.
    $markup .= '</div>';
    return $markup;
}
Step 3 – The filter will change the default <h2> tag to <h4> tag. Update this by replacing <h4> in the code with any heading tag needed. Click the “Update File” button to apply changes.
Note:
Please keep in mind that you need to replace the h4 tag with your needed tag in both places within the code to make this work – one is the opening tag, and the other one is the closing tag (just like we have used <h4> in both places in the code above).
Default Tag

Heading Tag after adding the Filter

 
			
		