Cannot download and install application from apple store on iPad Air 4

Are you unable to download just this specific App - or any App from the App Store?

If you are experiencing difficulties with downloading any Apps to your iPad:

If you can’t download or update apps on your iPhone or iPad – Apple Support

You should also check your ScreenTime restrictions:

• Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases > Adding Apps - ensure that this permission is set to Allow
• Settings > Screen Time > Content & Privacy Restrictions > iTunes & App Store Purchases > Deleting Apps - ensure that this permission is set to Allow

i cant install anything on my mac running on big sur and on my ipod touch