register_taxonomy( string $taxonomy, 
array|string $object_type, 
array|string $args = array() )

Example 1:

/* Register Type */
$type_labels = array(
  'name'=> __('ST_AI Types','st'),
  'singular_name'=> __('ST_AI Type','st')
);

register_taxonomy(
  'st_ai_type',
  'st_ai', 
  array(
    'labels'=>$type_labels,
    'show_ui' => false,
    'show_admin_column'=>true, // show the column in admin
    'show_in_rest' => true, // for Block Editor
    'hierarchical'=> false, // false for tag and true for category,
    'show_in_quick_edit' => false, // whether show in  QuickEdit
    'rewrite' => array('slug'=>'st_ai_type')
    )
);