Put advertisements.gsc in %localappdata%/Plutonium/storage/<t5>/scripts/<mp|sp>
and add these lines below in your dedicated.cfg
set sv_messages 1
set sv_messagesdelay 35
set sv_message1 "^1Message 1"
set sv_message2 "^2Message 2"
set sv_message3 "^3Message 3"
set sv_message4 "^4Message 4"
set sv_message5 "^5Message 5"
set sv_message6 "^6Message 6"
set sv_maxmessages 6
set sv_welcome 1
set sv_welcomemessage1 "^1Welcome 1"
set sv_welcomemessage2 "^2Welcome 2"
set sv_welcomemessage3 "^3Welcome 3"