ServiceNow outbound REST functionality allows you to retrieve, create, update, or delete data on a web services server that supports the REST architecture.

A REST message can be sent by a REST workflow activity or by using the RESTMessageV2 script API. You can run REST messages from a MID Server which allows the message to communicate with REST providers on an internal network.

This KB talks about an exception "AADSTS90014: The required field 'scope' is missing from the credential" which is triggered when we perform a REST outbound call from servicenow to third party using Oauth as basic authentication

In this scenario , OAuth application registry entry is defined with the respective grant type based on the third party configurations along with scope and profile information. Client credentials is used as grant type

Setup OAuth

An outbound REST call is configured with the above OAuth profile as the Basic Authentication in the REST request. When tried to click on "Get OAuth token" button on the outbound REST message record , below exception is observed from third party in the response

"AADSTS90014: The required field 'scope' is missing from the credential"

Issue is with the scope field value not mapped to the profile record in oauth_entity_profile table. After mapping the scope to the respective profile record on this table from OAuth application registry, the token is successfully received from third party using the "Get OAuth token" button on the outbound REST record.