Studio 10.2 - HTTPClientWorker and OAUTH2Worker

[malkishtini at gmail.com]

 Hello team,
I have a new question today, it is about consuming an AWS REST API from Studio 10.2.

This is my first time to use the HTTPClientWorker and OAUTH2Worker in Studio 10.2, that's why I want to make sure that I'm on the right track.

My first attempt to connect to the REST API in AWS, when there is no authorization setup for the API, worked fine.
My second attempt to connect to the same API, after enabling the AWS IAM authorization, failed with error " 13019 - The OAUTH2Worker object assigned to $oauth2 does not contain an access token".
The API doesn't require a token for authorization, it only requires client access and secret access key which I'm passing to the API. So I wonder if this error is from Omnis or from the API??

I'm able to connect to the API using postman with no issues (by only passing the client and secret access key).

So before I dig more into this issue, I just wanted to see if anyone in this list was able to establish a successful connection from Studio 10.2/ Oauth2 to an API in AWS when the authorization is done using "AWS IAM" or that is not an option in studio 10.2 or..?

BTW, I'm using the HTTPWorker sample in studio 10.2 to test the connection and I tried to change the authorization type, but I got the same error with the 3 types.
It was suggested to me to read https://docs.aws.amazon.com/general/latest/gr/signing_aws_api_requests.html and use a signed URL for the request, but again, since I'm new to all this process, I wanted to check and confirm that I'm moving in the right direction.

Thank you in advance for all feedbacks.
Mayada