Sharing the IAM user credential is not an ideal way and have potential risk. It would be nice if updraftplus is able to authenticate with IAM User Role onto S3 bucket.
This idea was posted in UpdraftPlus - backup/restore plugin and tagged crdential, iamrole, security on May 30, 2023 by 
Sven.
Hi,
Please can you add more detail? This request is too terse to understand the reasoning and ideas involved.
David
I second this very useful feature to enhance your security, if it is possible
More info here: https://docs.aws.amazon.com/IAM/latest/UserGuide/id_roles.html
AWS Roles don’t require key rotations and are more security because of how they connect and authenticate with external systems. This would be a preferred approach to IAM Users