Unable to view bills following IAM changes for Billing Console

Whatever permissions I set for an IAM user, I keep getting a "You need permissions" error when trying to view my bills. I have even tried actions . . The account has a Service Control Policy which allows everything. In CloudTrail, the event name which is causing Access Denied is "GetPaymentPreference", but there is no IAM permission of that name. I can see the bills by logging in as Root.

I have followed the advice here: https://aws.amazon.com/blogs/aws-cloud-financial-management/changes-to-aws-billing-cost-management-and-account-consoles-permissions/ to update the IAM policy. I also tried adding a . policy to this iam user, and that didn't help either. I checked the SCPs on this account, and they are not restricting.

The error message on the Bills page of Billing and Cost Management says "You Need Permissions You don't have permission to access billing information for this account. Contact your AWS administrator (etc ...)"

The relevant parts of the CloudTrail event looks like this:

{
    "eventVersion": "1.08",
    "userIdentity": {
        "type": "IAMUser",
		...
    },
    "eventSource": "billingconsole.amazonaws.com",
    "eventName": "GetPaymentPreference",
    "awsRegion": "us-east-1",
    "errorCode": "AccessDenied",
    "eventType": "AwsConsoleAction",
    "managementEvent": true,
}

How do I work around this so that the IAM user can see bills in this account? What is the IAM action related to the event called "GetPaymentPreference". Thankyou.