Popup not appearing on our staging site

We are testing OptinMonster on a client staging site. We have set up a free OM account for testing and have installed the plugin. It appears to be connected to OM. We have disabled the .htpasswd protection on the staging site. We created a simple test popup to appear on any page but it never does. We see our test campaign in WP admin/OM/Campaigns, with a status of Published.

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