functions.php

<?php
/**
 * Register the custom taxonomy.
 */
add_action( 'init', 'register_taxonomy_article_type' );
function register_taxonomy_article_type() {
  
  register_taxonomy( 'article_type', 'post', array(
    'label' => 'Article type',
    'hierarchical' => true,
    // This taxonomy should only be visible in the admin menu.
    'public' => false,
    'show_ui' => true,
    'meta_box_cb' => false,
  ) );

}

/**
 * Populate the ACF field with terms from the custom taxonomy Article type.
 */
add_filter( 'acf/load_field/name=article_type', function( $field ) {
  
  // Get all taxonomy terms
  $article_types = get_terms( array(
    'taxonomy' => 'article_type',
    'hide_empty' => false
  ) );
  
  // Add each term to the choices array.
  // Example: $field['choices']['review'] = Review
  foreach ( $article_types as $type ) {
    $field['choices'][$type->slug] = $type->name;
  }

  return $field;
} );

nice. how to sync it with taxonomy to update it based on acf select field?