how can I add people to protection ?

Hello sorry for bothering, Nick help me with the grief that happened on my house and I'm really thankful to him for all the help, but I run into a problem with the protection, I can't add people in, Nick gave me the command to do it but when I tried I get " too few arguments ./region addmember <id> <members...> " I'm not sure what to do, the people that I'm trying to add are Sylentnighmare, Gmyers and Agito_Regashi in case adding people is something I'm not allow to do.

thank you everyone