It's there, but you must disable ' Ignore "limit per store" rules '
https://docs.nopcommerce.com/en/running-your-store/content-management/message-templates.html Filtering: You can search for message templates by keywords or store. Keywords are used to search in the name, body or subject of a message template. The list of available stores is shown if you have more than one store and the Performance → Ignore "limit per store" rules (sitewide) setting on the Catalog settings page is not active.