Go to IAM Dashboard Create a new group (in IAM).

Name a group, then click on 'Next Step'.
 

Choose Custom Policy and click Select.
 

Fill in the Policy Name and Document using the below parameters.

 {  "Version": "2012-10-17",
  "Statement": [
    {
      "Action": [
        "autoscaling:Describe*",
        "cloudwatch:Describe*",
        "cloudwatch:List*",
        "cloudwatch:Get*",
        "ec2:Describe*",
        "ec2:Get*",
        "ec2:ReportInstanceStatus",
        "elasticache:DescribeCacheClusters",
        "elasticloadbalancing:Describe*",
        "sqs:GetQueueAttributes",
        "sqs:ListQueues",
        "rds:DescribeDBInstances",
        "SNS:ListTopics"
      ],
      "Effect": "Allow",
      "Resource": "*"
    }
  ]
}

For more information regarding the policy setup and controlling User Access to your account, please refer to this Article

Click Create Group at the bottom of the page. (This specific policy set up gives the aforementioned, newly named group read-only access to all relevant AWS services currently supported by BlazeMeter's integration.  Now that the new policy is set save the group creation.)
 

Now go to Users and click Create a new user.(Create a new user (sign up) or login in with your user (these are the credentials we’ll be providing) to the BlazeMeter integration with AWS CloudWatch.)
 

Write down your Access Key ID and Secret Access Key. (Now let's assign the newly created user to a group we created a few steps earlier.)

Choose a user and click add User to Groups.
 

Select the right group.