The following steps explain how to redeem promotional codes for Infinity Wars:
Step 1) If you haven't already, download Infinity Wars Reborn from Steam and create your free account.
Step 2) Launch Infinity Wars and input your login information
Step 3) From main screen, navigate to "Store" tab
Step 4) From "Store" tab, navigate to "Promotional Codes" tab
Step 5) Input your promotional code in available box and click "Redeem"