• Go to Rapid Credits API
• Make sure you’re in the Step 1: Apply Coupon endpoint
• Scroll down to the body and change the coupon code text with your coupon ADD_YOUR_COUPON_HERE → XYZCOUPON
• Press [Test Endpoint] button at the top — wait for the response

To verify:

• From the left sidebar click the Step 2: Check Account Balance endpoint
• Press [Test Endpoint] button at the top — wait for the response

Have fun hacking with APIs.
Peace!