Hi,
Please try different web browers to access below website to download the microsoft remote desktop.
https://apps.apple.com/app/microsoft-remote-desktop/id1295203466?mt=12
If it does not work, you can also download the beta version using below link:
https://install.appcenter.ms/orgs/rdmacios-k2vy/apps/microsoft-remote-desktop-for-mac/distribution_groups/all-users-of-microsoft-remote-desktop-for-mac
For your reference: https://learn.microsoft.com/en-us/windows-server/remote/remote-desktop-services/clients/remote-desktop-mac
For apple app store problem, we suggest you should contact the Apple Support for help.
https://support.apple.com/
Thanks,
Eleven
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