I am not able to figure out the way to add origin settings to cloudfront

I am setting up S3 to host static website and distributed with CloudFront. So far all good but now i want to add the origin settings available in CloudFront to make s3 available to CloudFront.

I am talking about above settings, where some settings might be incorrect but would want to implement it.

Tried following the bellow documentation:

but I am confused and getting error on

aws_cloudfront_origin_access_identity.origin_access_identity.iam_arn

how do I declare it ?