There's a link in the Mobile Ed resource NT221 textbook to The Return of the King:

I don't own this, so when I click on it I get the (expected) "You don't have a license to view this resource" message:

But the problem is, this isn't a resource sold on Logos.com; it's on Vyrso.com! But I don't know that yet (of course), so I blithely click on the "Visit Logos.com" link, and I get this error page:

Turns out the resource in question is this one on Vyrso.com:

Here's the link for it: https://vyrso.com/product/39199/revelation-and-the-end-times-participants-guide-unraveling-gods-message-of-hope
First, you need to get the links right.
Second, given that resources can move from Vyrso to Logos when books get upgraded to Logos editions, you probably shouldn't hard code the website location, but rather have the smarts to figure out which website it's on and the proper link on the fly, given the resource ID; in other words, there should be some unique resource ID which doesn't change if a resource gets upgraded from Vyrso to Logos.