At this time PhoneCheck doesn't support macOS Monterey and you may encounter an error when trying to launch PhoneCheck on macOS Monterey. We recommend macOS Catalina or Big Sur.
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​Download Big Sur - App Store

Download Big Sur through the Terminal:

Input :

softwareupdate --fetch-full-installer --full-installer-version 11.6.1

or the following for a list of installers

softwareupdate --list-full-installers