What's the name of this catholic chant?

I attended a ceremony held at the Basilica di Santa Maria Maggiore in Rome on 07/12/2021, and the last chant really impressed me, but I have no clue on how to go to find it. I tried searching an enormous list of Gregorian chants online, but nothing. I also cannot understand the words, and so I ran out of ideas on where to go from here... This is the link to the small segment I recorded: https://drive.google.com/file/d/1yuM8OF7bIVDzRSvOum7OkEudP5V0xjn1/view?usp=sharing Can anyone help me here? Any ideas where should I look to find it?