I got access token which I am using to get IDP token. When I get IDP token and run in postman by adding it in a header and performing GET request to endpoint https://outlook.office.com/api/v2.0/me/contacts, it gives an error like below.
This probably means that the IdP Access Token is expired. Auth0 doesn’t ask for a refresh token when authenticating through the Microsoft Account strategy, so this IdP Access Token is basically useful for actions taken immediately after login (e.g. obtain some additional profile info from a rule) or shortly thereafter.
If your application core functionality depends on the IdP token to access an external API the suggestion would be to issue a separate request to get an access token (and refresh token if it makes sense) directly from the IdP.