I need a procedure for my mod and I don't know how to do it

Hello people from the forum, sorry if sometimes it seems that I write badly, but it is because I do not know English and I am using the google translator, I am making a mask mod for the rp server that I am doing with a friend, but I want you to When someone puts on the mask, the nickname does not appear so that they cannot know who the one with the mask is, I would but I don't understand anything.