Currently external usage is limited by a regex in the Maps varnish configuration. To have your site added to that list, please file a Phabricator task in the SRE project with the following information:
- Link to site which you want to use Wikimedia Maps on
- Purpose of using maps / details about your project
- Which Wikimedia Affiliate is backing/supporting this project
Using this link will prefill the form for you.
Prior to August 2021, requests were made on T261694, that task is no longer used.