Usage
add_action( 'added_usermeta', 'your_callback_function', 10, 4 );Action Callback:
function your_callback_function( $wpdb->insert_id, $user_id, $meta_key, $meta_value ) {
// Your code here
}Parameters
$wpdb->insert_idParameter 1
$user_idParameter 2
$meta_keyParameter 3
$meta_valueParameter 4
⚡ Action Hook
Action hooks allow you to insert custom code at specific points during WordPress execution. Actions do not return any values.