Our Lady specifically asked at Fatima that we insert this prayer into each decade when we pray the Rosary.
These are the other prayers we were taught at Fatima:
My God, I believe, I adore, I trust and I love you. I beg pardon for those who do not believe, do not adore, do not trust and do not love you.
When we offer something to God
Oh my Jesus, it is for love of you, in reparation for the offenses committed against the Immaculate Heart of Mary, and for the conversion of poor sinners.
Most Holy Trinity, I adore you! My God, my God, I adore you in the most blessed Sacrament.
The Angel’s Prayer
With the Blessed Sacrament suspended in mid-air, the Angel of Fatima prostrated himself and prayed,
Most Holy Trinity — Father, Son and Holy Spirit — I adore you profoundly. I offer you the most Precious Body, Blood, Soul and Divinity of Jesus Christ — present in all the tabernacles of the world — in reparation for the outrages, sacrileges and indifference by which He is offended. By the infinite merits of the Sacred Heart of Jesus and the Immaculate Heart of Mary, I beg the conversion of poor sinners.