Go to JuicyAds website, login into your publisher account and click on 'Sell Ads' tab:
Find the website you want to import popunder(direct link) from:
On the next page, you will see popunder codes. DON'T USE THEM! AdSpyglass supports only direct links.
Scroll down the page. If you see Direct Url you may import it in AdSpyglass panel
If you see the same text as on the screenshot below, you have to request a direct URL first by sending email to email@example.com
!!! If you import the popunder zone without Direct URL request, JuicyAds will not count your traffic.