It is just a prayer that honors the Virgin Mary and seeks her intercession. The specific timing of when it can be prayed could vary determined by person or Group methods. 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/