You log on to the ApsaraMQ for RabbitMQ console as a RAM user, and the RAM user is not granted the permissions to view monitoring data.

To resolve this issue, use your Alibaba Cloud account to attach the AliyunCloudMonitorReadOnlyAccess policy to the RAM user. Then, the RAM user has the permissions to view monitoring data. For more information, see Step 2: Grant permissions to the RAM user.

The content of the CloudMonitor permission policy is:
{
    "Version": "1",
    "Statement": [
        {
            "Action": "cms:QueryMetric*",
            "Resource": "*",
            "Effect": "Allow"
        }
    ]
}