It is just a prayer that honors the Virgin Mary and seeks her intercession. The specific timing of when it is actually prayed may vary based on unique or Group tactics. The hymn is sung (utilizing the English translation "Hail, Holy Queen enthroned previously mentioned") by a choir of nuns https://encapsuladosvip.com/vita-pro-nobis-descubra-os-beneficios-dessa-incrivel-planta-medicinal/