Once it’s active normally within 24 hours, you’d then need to set it up using the steps found Here:

21 diverts all calls
61 diverts calls you don’t answer in 15 seconds
67 diverts calls when you’re on another call
If you want to…
Set up Call Divert: Press *(Code)*(Number to divert to)#
Check Call Divert: Press *#(Code)#
Turn off Call Divert: Press #(Code)#