Unable to create Subscription for Webhook using Microsoft Graph API for a particular document in Onedrive to get Request when the document is updated

I was trying to create a webhook subcription for a particular document in Onedrive to get the request while the file is updated but I was not able to create the subscription. Here is my request

POST /v1.0/subscriptions HTTP/1.1
Host: graph.microsoft.com
Authorization: Bearer
Content-Type: application/json
Content-Length: 297

{
    "changeType": "updated",
    "notificationUrl": "https://contoso.azurewebsites.net/api/webhook-receiver",
    "resource": "/me/drive/root:/file.xlsx",
    "expirationDateTime": "2022-01-01T11:23:00.000Z",
    "clientState": "client-specific string"
}

I am getting following response

{
    "error": {
        "code": "InvalidRequest",
        "message": "resource '/me/drive/root:/file.xlsx' is not supported.",
        "innerError": {
            "date": "2021-12-08T16:49:12",
            "request-id": "85ae70c6-2f43-422c-8e26-91ba749f08da",
            "client-request-id": "85ae70c6-2f43-422c-8e26-91ba749f08da"
        }
    }
}

But when the resource field is changed to /me/drive/root (i.e for my drive root folder). Webhook Subscription is successfully created. Here is my request body:

POST /v1.0/subscriptions HTTP/1.1
Host: graph.microsoft.com
Authorization: Bearer`
Content-Type: application/json
Content-Length: 282

{
    "changeType": "updated",
    "notificationUrl": "https://contoso.azurewebsites.net/api/webhook-receiver",
    "resource": "/me/drive/root",
    "expirationDateTime": "2022-01-01T11:23:00.000Z",
    "clientState": "client-specific string"
}

I am getting following response:

{
    "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#subscriptions/$entity",
    "id": "14bc7474-1493-4205-bc5e-ededbf5",
    "resource": "/me/drive/root",
    "applicationId": "f5a98a64-c08b-48c3-917a-f03c6466",
    "changeType": "updated",
    "clientState": "client-specific string",
    "notificationUrl": "https://contoso.azurewebsites.net/api/webhook-receiver",
    "notificationQueryOptions": null,
    "lifecycleNotificationUrl": null,
    "expirationDateTime": "2022-01-01T11:23:00Z",
    "creatorId": "767b3902-2804-40d9-817d-5e58a681",
    "includeResourceData": null,
    "latestSupportedTlsVersion": "v1_2",
    "encryptionCertificate": null,
    "encryptionCertificateId": null,
    "notificationUrlAppId": null
}

So can anyone suggest me with correct resource for webhook subscription for a particular document?