Here are the instructions we received from Wargaming to help you build the activation guide:

"For additional redemption instructions, please refer to this link How to redeem a Bonus Code:

  1. Go to Activation page
  2. Input the code and press REDEEM (Allow ~24h delivery processing time).
  3. You are done
  4. Warning! Only 1 code can be activated per account. The codes are valid till Sept 1st 2020"