Fortunately, there are several ways to get a compatible version of Pages for your hardware. 1. The "Purchased" Trick (The Most Reliable Method)
The most reliable way to get an older version is to re-download it from your account history. This works if you have ever downloaded Pages in the past using your Apple ID. on your Mac. Click on your icon in the bottom-left corner. in your list of previously purchased apps. (cloud) icon.
Apple does not list older versions in the App Store. Instead, they host specific installer files on their Support servers. These are the most reliable sources.
If you want, I can: