We have a case where we are trying to fetch the calendar events using the getSchedule api, where we are using the client credentials flow and given the access policy to the mail-enabled security group with the user in the shared maill box

Question

we are trying to use the client credentials flow token to fetch the free busy events of the users

so we have given the application access policy to the mail-enabled security group with a single-user email which is a shared email

so when we try fetching the events we get the below response from the graph API

{"error":{"code":"ErrorAccessDenied","message":"Access to OData is disabled."}

but when we have given direct access policy to the user mail enabled email address
we can fetch the free busy data

can someone please help with this