TenantGuidNotFound when trying to send email using Microsfot GraphAPI

I am trying to send an email using Microsoft GraphAPI inside my Laravel app. I am able to successfully get an access token through this function.

public function getAccessToken() {
        $tenantId = 'someID';
        $scope = 'https://graph.microsoft.com/.default';
        $appId = 'someAppID';
        $secretId = 'secretID';
        $secret = 'someSecretString';
        $url = "https://login.microsoftonline.com/{$tenantId}/oauth2/v2.0/token?scope={$scope}&client_id={$secretId}";

        $config = [
            'grant_type' => 'client_credentials',
            'client_id' => $appId,
            'client_secret' => $secret,
            'scope' => $scope,
        ];

        $response = Http::asForm()->post($url, $config);

        $data = $response->json();

        $token = Arr::get($data, 'access_token');
        
        return $token;
    }

When I decode the received access token using jwt.io, I get this.

{
  "aud": "https://graph.microsoft.com",
  "iss": "https://sts.windows.net/**********************/",
  "iat": 1727514977,
  "nbf": 1727514977,
  "exp": 1727518877,
  "aio": "k2BgYGiT2uLUtyghU2/p5IaN16YKAAA=",
  "app_displayname": "Mailer Oauth2",
  "appid": "***************************",
  "appidacr": "1",
  "idp": "https://sts.windows.net/***************************/",
  "idtyp": "app",
  "oid": "c4addf3b-ab49-4270-bbf8-a2a4d832c560",
  "rh": "0.ARMBkUlDtYDgK02i7VB0sFJDagMAAAAAAAAAwAAAAAAAAAAUAQA.",
  "roles": [
    "Mail.ReadWrite",
    "Mail.ReadBasic.All",
    "Mail.Read",
    "Mail.Send",
    "Mail.ReadBasic"
  ],
  "sub": "c4addf3b-ab49-4270-bbf8-a2a4d832c560",
  "tenant_region_scope": "EU",
  "tid": "*************************************",
  "uti": "bC3CrECPGEOLobarnNDrAA",
  "ver": "1.0",
  "wids": [
    "0997a1d0-0d1d-4acb-b408-d5ca73121e90"
  ],
  "xms_idrel": "10 7",
  "xms_tcdt": 1727427193
}

Under the roles attribute, I can see that Mail.Send is present.

When I try to send an email using this code

$emailData = [
            'message' => [
                'subject' => [$this->subject],
                'body' => [
                    'contentType' => 'HTML', 
                    'content' => $newTemplate, 
                ]
            ],
                'bccRecipients' => [
                    [
                        'emailAddress' => [
                            'address' => $this->mails->toArray()
                        ]
                    ]
                ],
                'attachments' => [
                    [
                        '@odata.type' => '#microsoft.graph.fileAttachment',
                        'name' => basename($srcImage),
                        'contentBytes' => base64_encode(file_get_contents($srcImage)), 
                        'contentId' => 'image', 
                    ],
                ],
        ];

        
        $response = Http::withToken($this->token)
            ->post("https://graph.microsoft.com/v1.0/users/{$this->email->email}/sendMail", [
                'message' => $emailData['message'],
                'saveToSentItems' => 'true', 
            ]);

But I receive this error

{"error":{"code":"OrganizationFromTenantGuidNotFound","message":"The tenant for tenant guid '***************************' does not exist.","innerError":{"oAuthEventOperationId":"d630a3bf-f7b2-4373-872f-6618f21d7429","oAuthEventcV":"bXHKl4PYUfE8FIF62ShkHA.1.1","errorUrl":"https://aka.ms/autherrors#error-InvalidTenant","requestId":"e131128d-d6f1-43da-85ac-88799cac7cac","date":"2024-09-28T09:30:39"}}}

This is a screenshot from my Azure app (App Permissions tab)

I have searched the internet and found out that I should use keyword 'common' when obtaining an access token, instead of using actual tenantID... I have tried it, but I receive error that tenantID is invalid and I can't obtain access token.

https://login.microsoftonline.com/common/oauth2/v2.0/token?scope={$scope}&client_id={$secretId}

I have selected multitenancy inside the Azure app, as you can see on the screenshot:

Honestly, I am not very experienced with Microsoft Azure... I assume the problem might be in some Azure definitions, but I have no idea where. Any help is appreciated.

The problem was in the getAccessToken() function. I was sending a request to the wrong endpoint, and therefore the obtained access token was wrong. The correct endpoint URL is

https://login.microsoftonline.com/common/oauth2/v2.0/token

More info on this link: https://learn.microsoft.com/en-us/graph/auth-v2-user?tabs=http