I tried today to activate "Proximity Beacon API" in a new project, but its seems to be no more available in the API search in https://console.developers.google.com. In my older project "Proximity Beacon API" is still activated and working but its now tagged as PRIVATE.
I didnt found any announcement from Google that this API will be no more available. Have someone (e.g. from Google) more information about this?
UPDATE:
according to this issue tracker comment https://github.com/google/beacon-platform/issues/57#issuecomment-716099762 Google have a turn down plan for the Beacon Platform (including the Proximity Beacon API)