You are under monetizing this ad unit. You should add more bidders, ideally at least five before you set PubGuru Header Bidding live.
Step 1: Get your site ready for approval – traffic is clean, clear navigation, valuable and family-friendly content, ads are not prone to accidental clicks, etc.
Step 2: Check Ad Network SOP’s
Step 3: Sign up and get your site approved with at least 5 bidders before you go live.