Archive page for custom post type

Hi. I’d like to create a custom archive template page for a custom post type and I am used to traditional themes as opposed to full site editing style.

Typically I would, in the child theme, copy the archive.php file to archive-myposttype.php and implement the loop there.

I’m not finding any documentation of how this is expected to be achieved and would appreciate input. In the meantime just displaying the posts in a plugin.

Thanks much.