Magento 2.3.2 Downloadable Product Sample URL and Link not working

[vcr7]

Hello. We're trying to embed a flippingbook link (http://cld.bz/users/trial-UEsGr/SOLAR-SYSTEM-Public-View) on a  Magento 2 Downloadable Product. We created a downloadable product and added the flippingbook link but we're getting the following error.

Uncaught DOMException: Failed to execute 'pushState' on 'History': A history state object with URL 'https://cld.bz/users/trial-UEsGr/SOLAR-SYSTEM-Public-View/nload/linkSample/link_id/3/' cannot be created in a document with origin 'https://magento-8833-0.cloudclusters.net' and URL 'https://magento-8833-0.cloudclusters.net/downloadable/download/linkSample/link_id/3/'.

I have added the flippingbook as a sample of the downloadable product as well. To see the error live, please check this - https://magento-8833-0.cloudclusters.net/grade-3-english-content-book.html and click on the sample file. 

I've uploaded two screengrabs as well. This video - https://drive.google.com/file/d/1-Q3N5YXi3mOdesC6xOlHs5YskkRZ0Ktn/view?usp=sharing, shows how a customer would access the flippingbook. You can see the original URL of the downloadable product file.

This video - https://drive.google.com/file/d/1-Q3N5YXi3mOdesC6xOlHs5YskkRZ0Ktn/view?usp=sharing, shows how we added the http://cld.bz/users/trial-UEsGr/SOLAR-SYSTEM-Public-View URL into the product.

Please advise.

[praful-rajput]

Facing the same issue while using the LINK option for downloadable products.

I added URL like https://mysite.com/var/import/books/abc.pdf 

As per few comments, If I'll keep it under pub/media then anybody can download the file using URL without any restriction. Please guide me.

It is showing me an error like "Something went wrong while getting the requested content."