Popup not displaying page content (empty)

Hello,

I’ve added a link trigger in an formidable form to open de Privavy Policy page in a pop-up. However when i click on the link the popup opens but is empty.
In the Chrome console i see the following error. Do you know what this means?

GET https://www.buurtbosch.nl/wp-json/wp-post-modal/v1/any-post-type?slug=privacyverklaring 404 ()
send @ 7qprl.js:5
ajax @ 7qprl.js:5
(anonymous) @ 7qprl.js:266
dispatch @ 7qprl.js:4
r.handle @ 7qprl.js:4
7qprl.js:280 404

Thanks

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