Adding tag automatically on post save

Hello!

Could you please help me on my issue!

I am using edd front end submission If the vendor submits a new download I want to add automatically some tags.

Adding category is working perfectly but adding tags not working but the function works once when I click the update button in the admin area.

Do you guys have any idea I am a valued customer of edd, please?

This is My code:

<?php

add_action(‘save_post’,’add_tags_on_postsave’);

function add_tags_on_postsave($post_id){

global $post;
if ( get_post_type($post_id) != ‘download’){
return;
}

//adding a category works perfectly.
$categ = array( 10 );
wp_set_post_terms( $post_id, $categ, ‘download_category’ , true );

//adding tags not working but in the admin area when I click the update button.

wp_set_post_terms( $post_id, ‘Tag1,tag2,tag3’, ‘download_tag’, true );

}

?>