Reporting signin methods registered in your Azure AD

$accessToken = "eyJ0eXAiOiJKV1QiLCJub25j---------O_dHsdrcf4WCHPYI4M-jg"
$VerbosePreference = "continue"

# No need to edit below this line
$restParams = @{Headers = @{Authorization = "Bearer $accessToken"}}

Write-Verbose "Getting all users"
$userlist = New-Object System.Collections.ArrayList
$uri = "https://graph.microsoft.com/v1.0/users?`$top=999"
do {
    $r = Invoke-RestMethod $uri @restParams
    if($r.value) {
        $userlist.AddRange($r.value)
    }
    $uri = $r.'@odata.nextLink'
} while($uri)


# Function that processes a batch, returning report lines per auth method per user
function Process-GraphBatch
{
    [CmdletBinding()]
    Param
    (
        [Parameter(Mandatory=$true,Position=0)]
        [System.Collections.ArrayList] $Batch,

        [Parameter(Mandatory=$true,Position=1)]
        [System.Collections.ArrayList] $BatchUser
    )
 
    Process {
         
        Write-Verbose "Sending batch of $($Batch.count) requests"
        $batchBody = @{requests = $Batch} | ConvertTo-Json -Depth 7
        Write-Debug $batchBody
        $r = Invoke-RestMethod "https://graph.microsoft.com/beta/`$batch" -Method POST -ContentType "application/json" -Body $batchBody @restParams

        Write-Debug ($r | ConvertTo-Json)
        $r.responses | ForEach-Object {
            if($_.status -ge 400) {
                Write-Warning "Request failed with error $($_.body.error)"
            } else {
                $user = $BatchUser[$_.id - 1]
                $_.body.value | ForEach-Object {
                    [PSCustomObject] @{
                        UserPrincipalName = $user.userprincipalname 
                        ObjectID = $user.id
                        Method = $_.'@odata.type'
                        PhoneNumber = $_.phoneNumber
                        PhoneType = $_.office 
                        smsSignInState = $_.smsSignInState 
                        emailAddress = $_.emailAddress
                        displayName = $_.displayName
                        model = $_.model
                        attenstationLevel = $_.attestationLevel
                    }
                }
            }
        }
    }
}



Write-Verbose "Processing users into batches of 20 users (for speed)"
$report = $userlist | ForEach-Object `
    -Begin {
        # Initialize variables
        $inc = 0
        $batch = New-Object System.Collections.ArrayList
        $batchUser = New-Object System.Collections.ArrayList
    }`
    -Process {
        # Add user to batchUser and request to batch variable
        Write-Verbose "$inc / $($userlist.Count)"; $inc = $inc + 1

        $batchUser.Add($_) | Out-Null
        $batch.Add(@{
            id = "{0}" -f ($batch.Count + 1)
            method = "GET"
            url = "/users/$($_.id)/authentication/methods"
        }) | Out-Null

        # If the batch is 20 long, process it
        if($inc % 20 -eq 0) {
            Process-GraphBatch $batch $batchUser
            $batch.Clear()
            $batchUser.Clear()
        }
    }`
    -End {
        if($batch.Count -gt 0) {
            Process-GraphBatch $batch $batchUser
        }
    }

$report | Out-GridView

# Report unique users using the different methods
$report | group ObjectId | Foreach{$_.Group[0]} | group Method | Select Name, Count | sort Count -Descending