Cannot login vault with aws IAM auth method

I followed the docs https://www.vaultproject.io/docs/auth/aws
I keep getting

Error authenticating: Error making API request.

URL: PUT http://0.0.0.0:8200/v1/auth/aws/login
Code: 400. Errors:

* error parsing arn "arn:aws:iam::xxxxxxxxxxxx:root": unrecognized arn: "root" contains fewer than 2 slash-separated parts

Prob a config issue. Can you share all your vault write commands used to configure someone might spot the issue.
And also the vault login command you’re using to test this out.

Is there a reason you’re using 0.0.0.0 vs 127.0.0.1? That might be confusing the listener if you’re local with multiple interfaces, but it seems to be connecting fine so not the issue… just curious.