Use structure tag in custom post type url format permalink [closed]

Question

Is it possible to use structure tags in custom post type rewrite slugs?

add_action( 'init', 'test1' );
function test1()
{
    register_post_type( 'test1', array(
        'label' => 'test1',
        'public' => true,
        'rewrite' => array(
            'slug' => 'test1/%monthnum%',
        ),
    ) );
}

This does not work. I get a 400 Bad Request when I go to the URL of a post I create.

Example of the URL I am testing

• https://www.mysite.com/test1/02/articlename
• https://www.mysite.com/test1/2/articlename

(Month is Feb - 02 or 2 neither works)

I tried the techniques mentioned here. The link to the plugin mentioned did not work and the example defining post type in functions.php did not work (400 Bad request when attempting to go to URL).

Note: I figured this out - needed to flush my permalinks.