how can i download the new version of keynote

If your Mac is really running macOS 12.2 Monterey as suggested by your tag line, then you can't. The current version of Keynote requires macOS 12.3 at least.

Update your Mac to at least 12.3 from System Preferences ➜ Software Update.

Once updated, you can download Keynote from the Mac App Store app by clicking here ➜ https://apps.apple.com/us/app/keynote/id409183694?mt=12