Can't create graph account

Question

I want to use the metered graph apis. To that effect I create a resource as per the documentation:

az graph-services account create --resource-group bot --resource-name bot-bill --subscription <my subscription id> --location global --app-id <Application (client) ID taken from entra>

This returns:

{
  "id": "/subscriptions/<my subscription id>/resourceGroups/bot/providers/Microsoft.GraphServices/accounts/bot-bill",
  "location": "global",
  "name": "bot-bill",
  "properties": {
    "appId": "<my app id>",
    "billingPlanId": "53cd401e-1a5f-xxxx-xxxx-0a0ec1b2e798",
    "provisioningState": "Succeeded"
  },
  "resourceGroup": "bot",
  "systemData": {
    "createdAt": "2024-10-11T14:41:14.3095173Z",
    "createdByType": "User",
    "lastModifiedAt": "2024-10-11T14:41:14.3095173Z",
    "lastModifiedByType": "User"
  },
  "type": "microsoft.graphservices/accounts"
}

Afterwards I run the following command to verify that everything is good:

root [ / ]#  az resource list --resource-type Microsoft.GraphServices/accounts
[
  {
    "changedTime": "2024-10-11T14:41:19.637867+00:00",
    "createdTime": "2024-10-11T14:41:14.221286+00:00",
    "extendedLocation": null,
    "id": "/subscriptions/<subscription id>/resourceGroups/bot/providers/Microsoft.GraphServices/accounts/bot-bill",
    "identity": null,
    "kind": null,
    "location": "global",
    "managedBy": null,
    "name": "ntgr-bot-bill",
    "plan": null,
    "properties": null,
    "provisioningState": "Succeeded",
    "resourceGroup": "bot",
    "sku": null,
    "systemData": {
      "createdAt": "2024-10-11T14:41:14.3095173Z",
      "createdByType": "User",
      "lastModifiedAt": "2024-10-11T14:41:14.3095173Z",
      "lastModifiedByType": "User"
    },
    "tags": null,
    "type": "Microsoft.GraphServices/accounts"
  }
]

root [ / ]# az resource show -g ntgr-bot -n ntgr-bot-bill --resource-type Microsoft.GraphServices/accounts
{
  "extendedLocation": null,
  "id": "/subscriptions/<subscription id>/resourceGroups/bot/providers/Microsoft.GraphServices/accounts/bot-bill",
  "identity": null,
  "kind": null,
  "location": "global",
  "managedBy": null,
  "name": "bot-bill",
  "plan": null,
  "properties": {
    "appId": "<app id>",
    "billingPlanId": "53cd401e-1a5f-48c9-a888-0a0ec1b2e798",
    "provisioningState": "Succeeded"
  },
  "resourceGroup": "bot",
  "sku": null,
  "systemData": {
    "createdAt": "2024-10-11T14:41:14.3095173Z",
    "createdByType": "User",
    "lastModifiedAt": "2024-10-11T14:41:14.3095173Z",
    "lastModifiedByType": "User"
  },
  "tags": null,
  "type": "microsoft.graphservices/accounts"
}

However, when I try to connect to msgraph and subscribe to users/{bot_user_id}/chats/getAllMessages?model=B I get the following error:

Error creating subscription: 
        APIError
        Code: 402
        message: None
        error: MainError(additional_data={}, code='ExtensionError', details=None, inner_error=InnerError(additional_data={}, client_request_id='ccc5a76c-41c0-4652-b2a6-bd323e6e7216', date=DateTime(2024, 10, 11, 14, 43, 0, tzinfo=Timezone('UTC')), odata_type=None, request_id='b8c702aa-1ea2-4cc3-bf5c-7efc5f8052fa'), message='Operation: Create; Exception: [Status Code: PaymentRequired; Reason: To access this resource, the app must be associated with an Azure subscription, see https://aka.ms/teams-api-payment-requirements for details.]', target=None)

I'm using the python SDK to connect to msgraph with the following code:

  credential = UsernamePasswordCredential(client_id=client_id, tenant_id=tenant_id, username=username, password=password)
  client = GraphServiceClient(credential)


  async def create_subscription_for_all_chats(client, user_id=None):              
      expiration_time = (datetime.utcnow() + timedelta(hours=1)).isoformat(timespec="seconds") +  "Z"
      bot_user_id = "7f5c5038-5909-4191-8589-3e8399877e3c"                        
      # Create a subscription for all chats the user is involved in               
      subscription_body = Subscription(                                           
          change_type="created,updated",  # Track both new messages and updates   
          notification_url=f"{PUBLIC_IP}/webhook-endpoint",                       
          # Replace with your actual ngrok URL                                    
          lifecycle_notification_url=f"{PUBLIC_IP}/lifecycle",                    
          resource=f"users/{bot_user_id}/chats/getAllMessages?model=B",  # Subscribe to all messages across all chats
           expiration_date_time=expiration_time,  # Set expiration time            
           client_state="secretClientValue",  # Optional client state for validation
           latest_supported_tls_version="v1_2"                                     
       )                                                                           
                                                                                   
       try:                                                                        
           subscription = await client.subscriptions.post(subscription_body)       
           print(f"Subscription created for all chats of the chatbot: {subscription.id}")
           return subscription.id                                                  
      except Exception as e:                                                      
           print(f"Error creating subscription: {e}")                              
           return None  

I can successfully subscribe if I ommit the ?model=B parameter but in this case I don't receive any change notification if someone writes to the respective use. Any ideas what am I doing wrong?