To be able to talk to Salesforce from RINT we need to setup a connected app in Salesforce and the user that will access the API.

Add Connected App

1. Login to Salesforce (we used the https://login.salesforce.com)

2. Click the Cog then Setup you will end up on the page .../lightning/setup/NavigationMenus/home

   
   
   

3. Under section Platform Tools → Expand Apps and click on App Manager
   
   

   
   
   
   

4. Click New Connected App button

5. Enter 
   Connected App Name
   API Name
   Contact Email
   
   
   

6. Check the Enable OAuth Settings

7. 
   
   

   Enter the callback url. This is the url found on the Authentication page in RINT when creating a new OAuth.
   Or enter manually <baseUrl>/secure/RestfulClientAction.jspa

8. In the Selected OAuth Scopes select the access level, in our example we will use Full access (full) and Perform requests on your behalf at any time (refresh_token, offline_access)
   Note. Must have Perform requests on your behalf at any time (refresh_token, offline_access) to make it a refresh token, otherwise the connection dies.

9. 
   
   

   
   
   

10. Click Save

    
    
    

Set the Permission Set

Make sure the API user has enough permission, here is an example of adding a new permission set and adding that to a user.

1. Under section Platform Tools → Expand Users

2. Click New (or reuse existing, don´t click new view)

3. Enter a name such as API

4. Click System Permissions

5. Check API Enabled and Apex REST Services

   
   
   

6. 
   
   

   Click on Users

7. Click on the user that you will use for API access

8. Scroll down to Permission Set and edit. Assign the new API permission set to the user

9. Save and all done!

   
   
   
   

Some resources

Assign Permission Sets to a Single User

How Do I Enable API Access in Salesforce Lightning Experience by the Permission Set?

Create a Connected App

External tutorial blog post