Step 1: obtain one of the two templates below
Select a version you want to use and click on the file menu of Google Sheets and "Make a Copy"
Step 3: Create a client
Just click the button!
Step 4: Fill out the form
Name your client, doesn't really matter what you choose. Leave the next box blank, you do not need any redirects.
Step 5: Reveal your secret
Click on SHOW SECRET
You'll now see your secret
Step 5: Go to your sheet's Script Editor
Click on the Tools
menu and select Script Editor
Step 6: Select Script
By default it should take you to wow_bfa.gs, but just in case.. make sure it's selected!
Step 7: Enter in your Client ID and Secret
Copy Paste the Client ID and Secret from the dev portal into your script, then save the script and return to your sheet.
IT CAN TAKE UP TO 10 MINUTES FOR YOUR DEV ACCOUNT CREDENTIALS TO START WORKING!
(and sometimes longer, thanks blizz!)