CS6 Extended is not downloading on Mac

I bought Photoshop CS6 Extended version years ago. I'm trying to reinstall it on to my Mac. I am able to download the correct version on my desktop, but when I try to upload it - this notification appears  . The "Learn More" button directs me to this page, which bascially tells me to contact the developer of the app. Online support chat told me to post to this forum because "We do not offer chat support for this online service, but our forums may allow you to find answers." Can someone help me? My Mac is up to date with macOS Big Sur 11.2.3. Please help me!