And, also those Environment Variables are not working out in my case.
I used AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY instead.

Since in docs present in this site here, it says that using AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY is RECOMMENDED since they are recognized by all the AWS SDKs and CLI except for .NET, while AWS_ACCESS_KEY and AWS_SECRET_KEY are only recognized by Java SDK.