Hi,
I am creating a Workflow which makes a call to ION API.
I have specified all the parameters and also uploaded Service Account details in it.
While making Test to API call using 'Test' feature, it gives 'Invalid Grant' error(attached screenshot). It seems an OAuth issue.

The service account has an access key and secret key assigned to it.
Please suggest if any configuration might be missing or what all access it needs to make the API call successfully.
Please note that I am able to make call to APIs using same service account using ION API connection point.
Regards,
Ridhima