To change the OAuth Security Credentials , follow this sequence of steps:
Step 1: Click the gear icon (⚙️) → Setup→In the Quick Find box, type App Manager→Click App Manager.
Fig 1 : Manage connected Apps
Step 2: Verify that the circled permissions are there. If not, you may click edit and change them.
Fig 2 : View connected App details
Step 3: If the settings are correct and you are still experiencing errors, then you can either change the OAuth Consumer Key and Secret Key for the user or simply create a new Connected App. The following steps show you the process of configuring a new “Connected App” in Salesforce, and then using this new Connected App for BluSynergy access.
Back on the previous screen, click on the “New External Client App” button. You must perform this action while logged into Salesforce as the user under whose security context you want the BluSynergy API to operate.
Fig 3 : Edit Connected App
Click on the Drop Down button to edit connected app.
Step 4: Copy all the values from the previous setting (it is easier if you open the existing settings in a new browser window so that you can cut and paste the values) . The purpose behind this step is enable creation of a new OAuth Consumer Key and Consumer Secret under the security context of the currently logged on user.
Make sure the "Callback URL" is in this form (replace "yourcompany" with your assigned URL or "domain prefix", and change "blubilling-test" according to the system you are granted access to):
https://yourcompany.blubilling-test.com/salesforce/callBack
Fig 4 : Create new connected App
Step 5: When you click “Save” you will be see the new values for the Consumer Key and Consumer Secret. You will need these 2 values for the next steps
Fig 5 : Review Connected App
Step 6: Now click the “App Launcher” tab on the top row, and then the “BluSynergy” app.
Fig 8 : Salesforce Integration feature in BluSynergy