Each podcast on Hello Audio contains a field for tracking code headers that are used on the signup page. The signup page is where folks go to be added as a lister to a private feed, either for free or with a paid subscription.
The tracking code is most often a Meta Pixel or Google Tag, as well as other tools like ActiveCampaign which offer page view scripts. These codes update audiences with page view events to track page engagement.
You can find the code input field when first creating the private feed, or click "Edit" in your "Feed Details" right bar. Expand the optional fields to find the input. Paste your code and save changes.
You can use a pixel checker tool like Meta's Chrome Extension to confirm the header code is in place.
This is in addition to the Hello Audio feature of adding a tracking pixel to the subscribe pages of a feed (where the listener selects a podcast app).