Who receives the translation? Is this a meeting plugin or public API?

Signed-in realtime interpretation is a browser listening-and-translation tool. Audio from the selected source is sent to an online translation service; it is not fully offline processing that keeps all audio on your device. Translated text and speech return to the current page. They are not automatically sent to other meeting participants or added as a translation audio track in meeting software.

Use the official API documentation to check which developer interfaces are available. File translation uses projects and export tasks. In the signed-in realtime workbench, saved subtitles appear in History and session audio is not saved there.