The golden ampulla, which dates from 1661, is a flask in the shape of an eagle that holds the holy oil, which was consecrated in Jerusalem in March and will be used to anoint the king.

Source: https://indianexpress.com/article/explained/explained-global/king-charles-coronation-what-crown-jewels-will-be-used-in-the-ceremony-8547914/

The historical heart of the service, the anointing of the new monarch with holy oil, was the same solemn ritual it has always been.

Source: https://www.dailymail.co.uk/columnists/article-12057469/The-late-Queens-friend-LADY-GLENCONNER-compares-Saturdays-Coronation-Majestys-1953.html?ns_mchannel=rss&ns_campaign=1490&ito=1490

The holy oil has been created using olives harvested from two groves on the Mount of Olives, at the Monastery of Mary Magdalene and the Monastery of the Ascension, and will be used to anoint the King during the extravagant ceremony.

Source: https://www.thenational.scot/politics/23363460.holy-oil-the-orb-historic-objects-coronation/?ref=rss