Assume Policy For Cross AWS Account

assume_role.js

{
    "Version": "2019-08-17",
    "Statement": [
        {
            "Sid": "VisualEditor0",
            "Effect": "Allow",
            "Action": [
                "sts:DecodeAuthorizationMessage",
                "sts:GetAccessKeyInfo",
                "sts:GetCallerIdentity"
            ],
            "Resource": "*"
        },
        {
            "Sid": "VisualEditor1",
            "Effect": "Allow",
            "Action": "sts:*",
            "Resource": "arn:aws:iam::<acount-id>:role/clients/our-client"
        }
    ]
}