You can use the ONTRApages Plugin to host ONTRApages on your WordPress site! You don't need to integrate the site using the Pilotpress plugin; this can be done on any WordPress site. Of course, if you have a site that is already integrated using Pilotpress you can also add the ONTRApages plugin to host the landing pages.
The pages should NOT be hosted on any other domain in ONTRAPORT. Un-host them first before trying to add them to your WordPress site. We don't save the old hosting information anywhere, so if you think you might want to revert to hosting them separately, write down the URL for each page.
Then, to un-host them open the page for editing and click the Publish button, then click the Un-Host Landing Page button.
Then you can use the ONTRApages Plugin to select the landing page from the drop down - click ONTRApages >> Add New and select the page from the drop down!