CSV headers: InvitedUserEmailAddress, DispName, RedirectURL

AzureAD - Invite guest users.ps1

$cred = Get-Credential
Connect-AzureAD -Credential $cred
$invitations = import-csv C:\data\invitations.csv
$messageInfo = New-Object Microsoft.Open.MSGraph.Model.InvitedUserMessageInfo
$messageInfo.customizedMessageBody = "Hey there! Check this out. I created an invitation through PowerShell"
foreach ($email in $invitations) {New-AzureADMSInvitation -InvitedUserEmailAddress $email.InvitedUserEmailAddress -InvitedUserDisplayName $email.Name -InviteRedirectUrl https://wingtiptoysonline-dev-ed.my.salesforce.com -InvitedUserMessageInfo $messageInfo -SendInvitationMessage $true}