Assign Default Taxonomy to Post When Created

Question

I'd like to associate new posts created under a custom post type to automatically be given a custom taxonomy term. As a heads up here are the parameters

Custom Post Type Name: business_ser_dir_ltg
Custom Taxonomy Name: secondary-listing-category
Term Name: Business Services
Term Slug: business-services

function bus_default_terms( $post_id, $post, $update ){
if ( 'business_ser_dir_ltg' == $post->post_type) {

$default_term = '5480'; // ID of the required term
$taxonomy = "business-services"; // slug of the taxonomy

wp_set_post_terms( $post_id, $default_term, $taxonomy );

}
}
add_action( 'save_post', 'bus_default_terms', 30, 3 );

This is the code I created, but when I create a new post it does not automatically assign the term Business Services to the newly created post.

Answer 1

First of all, the third param of wp_set_post_terms must be a taxonomy slug, in this case, it's secondary-listing-category.

Second, the term ID should be in numeric type instead of string. Read the explanation here: https://developer.wordpress.org/reference/functions/wp_set_post_terms/#user-contributed-notes

Therefore, the correct code should be

function bus_default_terms($post_id, $post, $update){
    if('business_ser_dir_ltg' == $post->post_type){
        
        $default_term = 5480; // ID of the required term
        $taxonomy     = "secondary-listing-category"; // slug of the taxonomy
        
        wp_set_post_terms($post_id, intval($default_term), $taxonomy);
        
    }
}
add_action('save_post', 'bus_default_terms', 30, 3);

Answer 2

Thank you @Dao for your answer. I was able to figure out the solution. The answer is below:

/*Set Default Taxonomy to Business Services*/
function bus_default_terms($post_id, $post, $update){
    if('business_ser_dir_ltg' == $post->post_type){
        
        $default_term = 'Business Services'; // Name of the required term
        $taxonomy     = "secondary-listing-category"; // slug of the taxonomy
        
        wp_set_post_terms($post_id, $default_term, $taxonomy);
        
    }
}
add_action('save_post', 'bus_default_terms', 30, 3);