Vatican News’ explanation of A Special Urbi et Orbi Blessing:
The Pope announced that on Friday, March 27, he will preside over a moment of prayer on the sagrato of St Peter’s Basilica, the platform at the top of the steps immediately in front of the façade of the Church. “I invite everyone to participate spiritually through the means of communication”, he said. The Director of the Holy See Press Office confirmed that the moment of prayer on Friday will be broadcast live from the Vatican, beginning at 6 PM Rome time.
Join the Pope and Catholics worldwide at 12:00 Noon today to pray for the victims of COVID-19 and an end to the pandemic. Pope Francis will grant an Urbi et Orbi (to the City of Rome and the World) blessing which carries with it a plenary indulgence.
In order to obtain the plenary indulgence:
join the Pope spiritually by watching the prayer at noon
have a spirit detached from sin (including venial sin)
pray for the Pope’s intentions (usually an Our Father, Hail Mary, and Glory Be), and, as soon as possible,
make a sacramental confession and receive Holy Communion.