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)
The Google beacon platform is deprecated as of December 7, 2020. The platform will shut down on April 1, 2021. After this shut down, beacons will no longer be supported within the Nearby Messages API.