When someone asks to use They/ Them pronouns?

I am sorry for the silly question. When someone asks you to use They/Them pronouns, how would you go on with the situation? My friend (Whom is a female) told me she wants everyone to start using They/Them pronouns. I would ask right now but she's going out of town. How would you use those pronouns? I know I used female pronouns but I'm trying to learn the correct way. I only know how to use thosepronouns when I'm mentioning more than one person. I don't quite know how to use the pronouns for singular usage. Thank you.