To integrate the order fulfillment app with the Salesforce API using OAuth 2.0 protocol, the identity architect should use aConnected App and OAuth scopes. A Connected App is a framework that enables an external application to integrate with Salesforce using APIs and standard protocols, such as OAuth 2.0. OAuth scopes are permissions that define the specific data that an external application can access or modify in Salesforce. To use OAuth 2.0 protocol, the identity architect needs to configure a Connected App in Salesforce and assign the appropriate OAuth scopes to it, such as “api” or “full”. References: Connected Apps, OAuth Scopes