This post will help you setup a trust between your Cribl Cloud instance and your AWS account. It follows the steps documented on the docs page for Cross-Account data collection.

This Rapid Adoption CloudFormation template can help automate the trust between your Cribl Cloud stack and your AWS Account. In order to keep the IAM policy limited to only resources that Cribl Cloud should have access to, the template will ask for specific S3 buckets and related SQS's.