Do you notice the default Comment Box and need to change it to Astra』s Comment Box on Custom Post Type?
Astra provides a filter using which you can replace the default Comments Box with the Astra』s Comment Box.
add_filter( 'astra_comment_form_all_post_type_support', '__return_true' );
You will need to add this filter to the Child theme』s functions.php.
Default Comment box –
Updated Comment box using the above-mentioned filter –
Note: If you are unable to find the Comments box on your Custom Post Types, you will need to enable it from the Types if using Custom Post Types plugin. Also here』s an article to help you locate this feature.