Hi @romanmg
Thanks for your comments!
It turned out that FilePreviews.io is not currently able to specify custom headers for the download request. However, they suggested trying putting the api_token = directly into the url of the download request and that has worked, i.e.:
I saw in @JustinC’s helpful post How To Setup API Authentication? that he said this method is not recommended because it’s less secure.
After doing some research, I understand that you’d never want to use this method where the URL is being exposed to the user’s browser. However, where the URL is only being used between apps directly via their APIs over https, then it can be acceptable. I will run this past a professional before I implement it and write a post telling others it’s the solution.
Cheers
Travis