This article will walk you through setting up a Slack App and then introduce you to adding Slack account using Postman.
1. Create a Slack App by navigating directly to the “https://api.slack.com/apps?new_app=1”. Fill out all the required fields. click on create App.
2. Scroll down and note the Client ID and Client Secret.
3. On the left navigation panel click OAuth & Permissions, add the following URL to your list of Redirect URLs: https://www.getpostman.com/oauth2/callback. And save it.
4. Open Postman, Now that we have a Slack App to authorize against, we will set up an OAuth 2.0 client. In Postman's Authorization menu, select OAuth 2.0 for the type and Once OAuth 2.0 is selected as the type, click the “Get New Access Token” button to open the OAuth configuration modal.
5. Please provide all these details and click on the “Request Token” button.
6. If you set up everything correctly, you should see a workspace window and provide a valid workspace name, click on the “Continue” button.
7. Provide a valid username and password, click on the "Sign In" button.
8. You would see a Slack authorization window and now click on the “Allow” button.
9. Finally, the "Access Token" will be generated.