The reason behind getting that error is because your token has wrong audience.
Please check what token you are using to call Graph API.
I tried to reproduce the same in my environment.
If you are using ID Token
instead of Access Token
, you may get error like below:

To know whether you are giving access token or id token, decode it in JSON Web Tokens - jwt.io.
For access token, aud
claim will be "https://graph.microsoft.com"
or "00000003-0000-0000-c000-000000000000"
For id token, aud
claim will be "your_app_client_id"
Choose the access token carefully with aud
as "https://graph.microsoft.com"
while calling Microsoft Graph API:

To get profile for current user, you can make use of below query:
GET https://graph.microsoft.com/v1.0/me
I got the profile successfully using access token like below:

Replace your scope with https://graph.microsoft.com/.default
while generating access token to avoid confusion.
Reference:
oauth 2.0 - Microsoft Graph API: Access token validation failure. Invalid audience - Stack Overflow
UPDATE:
In order to get authorization code, make the request by changing scope like below:
https://login.microsoftonline.com/your_tenant_id/oauth2/v2.0/authorize?
client_id=your_client_id
&response_type=code
&redirect_uri=xxxxxx
&response_mode=query
&scope=https://graph.microsoft.com/.default
&state=12345