1. You have to write your username without @ and under double qoute
   e.g
   if your user name is billy then in config file you have to use "billy"

2. Your WIF or private key code is not the private key generated during account creation but it is under your account - permission - show key for active
   e.g
   if your account login key is abc and under permission key is def then use def under config file

3. MAKE SURE TO REMOVE # after your command
   e.g

Under name of witness add:

witness = "yoursteemitusername"

remove

Under name of witness add:

witness = "yoursteemitusername"