I am unable to download Keynote on my MacBook Air running Big Sur
says must have 13 Max or latter. my computer is 13
[Re-Titled by Moderator]
MacBook Air 13″, macOS 11.7
If you've downloaded Keynote in the past, go to the Purchases section on the App Store and download it. You'll be offered to download a compatible version.
If not, you'd need to update macOS to macOS Ventura 13 as you currently use macOS Big Sur 11.7.
If this is not possible because you Mac is not compatible with this version of macOS, your last resort will be to use the online version of Keynote on iCloud.com.