I have Microsoft Premium solitaire installed on my Ipad Air But have been unable to download the Daily Challenges for a month. Hoew cn I fix this?

Perhaps your iPad is not running iPadOS 14 or later, required by Daily Challenges (it might be a matter of compatibility)

You can identify your iPad model correctly, using these instructions:--> Identify your iPad model - Apple Support.

You can discover what iOS/iPadOS version is running on your device in Settings>General>About>Software Version.

Then you can check this compatibility chart:

Regards

Giulio