How to Call SharePoint REST API from Postman using OAuth2 Authorization Flow

We’ll walkthrough how to Call SharePoint REST API from Postman using OAuth2 Authorization Flow

Prerequisites:

• SharePoint Site Collection in your Microsoft 365 (M365) Tenant
• Azure AD access to register an app (with an Azure Subscription linked to the Azure AD used by your M365 tenant)
• Basic knowledge of SharePoint REST API and OAuth2 Authorization code flow
• Postman tool to send HTTP requests

Implementation Steps:

1. Register an application in Azure AD and grant necessary SharePoint permissions.
2. Use Postman to build an HTTP request for obtaining an OAuth2 access token.
3. Send the HTTP request to SharePoint, including the OAuth2 access token obtained from Postman.

Step 1: Register an application in Azure AD and add SharePoint Permissions

1. Go to Azure AD (Directory linked to your M365 tenant)

2. Select App Registration > New Registration > Fill out the form

• Note: Redirect URL https://oauth.pstmn.io/v1/callback.