This filter is applied within the breadcrumb_navxt_trail class in the maybe_add_post_type_arg() function. This filter was introduced in version 5.4. It receives three parameters:
- $add_query_arg – (boolean)(required) The boolean decision whether or not to add the post type query argument to the URL to filter
- $type – (string)(optional) The name of the post type that is under consideration for addition to the URL
- $taxonomy – (string|NULL)(optional) The taxonomy name for the archive in question (may be null)