If I understand the code correctly, the plugin uses JsLocaleHelper to replace the text used in the frontend (the content of client.*.yml). server.*.yml, which for example contains the descriptions of site settings, remains unchanged.
Is “azy videos just an example of what you want to use the plugin for? The plugin was designed to replace a specific term across a large number of texts. Since this text only appears once in the forum, you could just edit the text directly without using the plugin. There is a guide on how to do that: Customize text in Discourse
