How to fix the AuthenticationError while trying to create teams meeting using the graph API

Question

I am building an web application to enable users to join Microsoft Teams meeting. For this I am using Azure Communication Service (ACS). I need to pass the meeting link to the ACS component to render the meeting. Until now what I have read, ACS only accepts meeting links created by the MS Graph API.
After exploring a bit. I found Graph Explorer to be pretty handy for get started with the Graph API.
To create the Teams meeting I am using this endpoint POST https://graph.microsoft.com/v1.0/communications/onlineMeetings
with a sample request body for meeting creation details:

  {
    "startDateTime": "2024-12-05T12:00:00Z",
    "endDateTime": "2024-12-05T13:00:00Z",
    "subject": "Your Meeting Subject"
  }

I observed that Graph explorer has Access Token tab which generates the Token itself.
On running the query, I got this response of AuthenticationError:

{
    "error": {
        "code": "AuthenticationError",
        "message": "Error authenticating with resource",
        "innerError": {
            "date": "2024-12-06T12:11:36",
            "request-id": "8bee9a59-e550-49d8-b535-4345743ac799",
            "client-request-id": "2b3a73be-d1f7-8c25-f0d1-89d73a44d157"
        }
    }
}

To dig more, I went through the application permissions and tried to add all the necessary permissions from delegate and application option for OnlineMeeting resource. Below is the screenshot for this:

I have verified that my application registration is active and I am having pay-as-you-go subscription.
I am not able to find out how to fix this thing, Grateful for any help regarding this.