Need to add sponsor banner before posts on Category archive page

Try this:

function sponsor_banner($post_count) {
  static $already_run = false;
  if (is_category('uncategorized')) {
    if ( !$already_run) {
?>
<img src="/path/to/banner.jpg">
<?php
      $already_run = true;
    }
  }
}
add_action('the_post', 'sponsor_banner');

A minor correction: The parameter passed to the_post hook is the post itself

function sponsor_banner($post) {
  static $already_run = false;
  if (is_category('uncategorized')) {
    if ( !$already_run) {
?>
<img src="/path/to/banner.jpg">
<?php
      $already_run = true;
    }
  }
}
add_action('the_post', 'sponsor_banner');

thanks for the code, But I have a problem trying to put the code gives me an error, the code is put in functions.php theme / yourtheme / functions.php? I tried but I get error when I add the code line?

The code needs to be added to your theme’s functions.php file.

If you have any other problems, please start a new topic, this one has been marked as resolved.