SharePoint Online - Add site collection admin using CSOM PowerShell

Question

I have one SharePoint site e.g. test1 - "https://abc.sharepoint.com/sites/test1".

I have granted SharePoint Administrator role to User1 in the Microsoft 365 Admin Center (Note - User1 does not have any permissions to the site test1 but has assigned a role of SharePoint Administrator through admin center)

I want to add the user User2 as a site collection admin to the site test1 using the PowerShell.

But when I am trying to connect to the site test1 using PnP command Connect-PnPOnline and credentials of User1, I am getting The remote server returned an error: (401) Unauthorized..

Is it possible to add site collection admin to the site test1 using CSOM PowerShell + User having SharePoint Administrator role(User1 in this case).

or is there any other workaround?

Please guide me on this.

Thanks!

Answer 1

“User1” cannot add new site collection admin to "test1" site collection using CSOM PowerShell.

"User1" must has Global Administrator permission can run the following script commands

$AdminURL = "https://contoso-admin.sharepoint.com/"
$AdminName = "[email protected]"

$SiteCollURL = "https://contoso.sharepoint.com/sites/test1/"
$SiteCollectionAdmin = "[email protected]"
 
#User Names Password to connect 
$SecurePWD = read-host -assecurestring "Enter Password for $AdminName" 
$Credential = new-object -typename System.Management.Automation.PSCredential -argumentlist $AdminName, $SecurePWD

Connect-SPOService -url $AdminURL -credential $Credential

#Add Site collection Admin
Set-SPOUser -site $SiteCollURL -LoginName $SiteCollectionAdmin -IsSiteCollectionAdmin $True