The term 'Add-PnPClientSidePage' is not recognized as the name of a cmdlet

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PS C:\WINDOWS\system32> Add-PnPClientSidePage Add-PnPClientSidePage : The term 'Add-PnPClientSidePage' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify that the path is correct and try again. At line:1 char:1 + Add-PnPClientSidePage + ~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : ObjectNotFound: (Add-PnPClientSidePage:String) [], CommandNotFoundException + FullyQualifiedErrorId : CommandNotFoundException PS C:\WINDOWS\system32>

[#2]

First thing first, you need to install PNP PowerShell. Also command-let "Add-PnPClientSidePage" is deprecated hence use Add-PnPPage instead.

https://pnp.github.io/powershell/articles/installation.html