1. Copy the key you have got after transaction. You can find the key in your profile on the site Oplata.info:
2. Firstly, you will need to download and install Battle.net client.
3. Run the Battle.net application and log in to your existing account or create a new one:
4. Enter the key on the activation page:
5. Success! Your game will be activated and binded to your Battle.net account.