Installing Lightroom 4 on a new computer?

After being transferred between 6 people on the chat help, I was advised to reach out here. I just got a new computer and am hoping to transfer Lightroom 4 from my old computer. Is there a way download the old software? Also, I was informed my serial number is reflected as "returned" - though it was not, I have used it for 7 years without issue, and I can still pull up the purchase (Amazon) with the indication that the return window expired. So if the download is possible - I'm hoping I can continue to use the serial number.

I understand that the software is now offered via the cloud. I have tried this, but had to delete it from my computer because Adobe seemed to be over-utilizing the processor even when it wasn't opened.

{Moved from Lightroom Cloud to Lightroom Classic Forum by Moderator}