Creating Script to extract last Sing In signInActivity from excluded Users from Azure CA

Dear Community

I try to create a Script what is fetching me out the last  signInActivity

and here is the place where I stuck and have no chance to coming forward

(I paste just the necessary columns from the Script $CustomObject is for another Excel Sheet )

##here I fetch the excluded Users from the Group and Store the Value into the Variable Member##

$ExcludeGroupMembers = @()

$ExcludeGroupMembers = foreach ($Object in ($CAPolicies.excludeGroupsId | Select-Object -Unique)) {
Write-Verbose -Verbose -Message "Getting exclude group members for policy $($Policy.displayName)..."

$Uri = "https://graph.microsoft.com/beta/groups/$Object"
$GroupName = { (Get-MsGraph -AccessToken $AccessToken -Uri $Uri -ErrorAction Stop).displayName }

$Uri = "https://graph.microsoft.com/beta/groups/$Object/members"
$Members = (Get-MsGraph -AccessToken $AccessToken -Uri $Uri).userPrincipalName| Sort-Object userPrincipalName

$CustomObject = New-Object -TypeName psobject
$CustomObject | Add-Member -MemberType NoteProperty -Name "Group" -Value $GroupName
$CustomObject | Add-Member -MemberType NoteProperty -Name "Members" -Value $Members

so far so good this works User Objects are stored into the Variable my next step here is to 

foreach the Members but here i stuck I allways get an error :

(404) Not Found. In Zeile:16 Zeichen:13 + $Response = Invoke-WebRequest -Method GET -Uri $ApiUrl -ContentType " ... + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : InvalidOperation: (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-WebRequest], WebException + FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeWebRequestCommand

###########################################

If I try it with a single User, for example email address removed for privacy reasons

https://graph.microsoft.com/beta/users/email address removed for privacy reasons?`$select=displayName,userPrincipalName,signInActivity,userType,assignedLicenses&`$top=999

it works and also when I try to select over all the User also  like here:

https://graph.microsoft.com/beta/users?`$select=displayName,userPrincipalName,signInActivity,userType,assignedLicenses&`$top=999

But if i just store the User into a Variable like

$TheUser = "email address removed for privacy reasons"

"https://graph.microsoft.com/beta/users/$TheUser?$select=displayName,userPrincipalName,signInActivity,userType,assignedLicenses"

i get an Error and also when I wanna use the Varible $Members from above 

i get the error

So this would be the Lines I try to run to get just the Selected Values from the Variable $Members

foreach ($Member in ($Members | Select-Object -Unique)) {
$ApiUrl = "https://graph.microsoft.com/beta/users/Member?

$select=displayName,userPrincipalName,signInActivity,userType,assignedLicenses"

$Result = @()

While ($ApiUrl -ne $Null) #Perform pagination if next page link (odata.nextlink) returned.

{

$Response = Invoke-WebRequest -Method GET -Uri $ApiUrl -ContentType "application\json" -Headers $headers | ConvertFrom-Json

}

if($Response.value)

{

$Users = $Response.value

ForEach($User in $Members)

{

$Result += New-Object PSObject -property $([ordered]@{

DisplayName = $User.displayName

UserPrincipalName = $User.userPrincipalName

LastSignInDateTime = if($User.signInActivity.lastSignInDateTime) { [DateTime]$User.signInActivity.lastSignInDateTime } Else {$null}

IsLicensed = if ($User.assignedLicenses.Count -ne 0) { $true } else { $false }

IsGuestUser = if ($User.userType -eq 'Guest') { $true } else { $false }

})

}

}

$ApiUrl=$Response.'@odata.nextlink'

}

$Result | Export-CSV "C:\LastLoginDateReport.CSV" -NoTypeInformation -Encoding UTF8

Would be really happy for any advice here because here i stuck now for a long Time 

Kind Regards,

Martin