I have an Automation Document snippet which attempts to:

Update AMI used by the specified Launch Template.

Create a new version of the Launch Template with the updated AMI.

However, I get the following errors at the last step:

Parameter validation failed:
Invalid type for parameter LaunchTemplateData.ImageId, value: ['ami-XXXX'], type: <class 'list'>, valid types: <class 'str'>
Invalid type for parameter SourceVersion, value: 5, type: <class 'int'>, valid types: <class 'str'>

Is there a way to cast/convert/manipulate parameter types?

Thank you.

{
  "parameters": {
    "LaunchTemplateId": {
      "type": "String"
    },
    "TargetAmiName": {
      "type": "String"
    }
  },
  "mainSteps": [
    {
      "name": "getLaunchTemplate",
      "action": "aws:executeAwsApi",
      "inputs": {
        "Service": "ec2",
        "Api": "DescribeLaunchTemplateVersions",
        "LaunchTemplateId": "{{ LaunchTemplateId }}"
      },
      "outputs": [
        {
          "Name": "Version",
          "Selector": "$.LaunchTemplateVersions[0].VersionNumber",
          "Type": "Integer"
        },
        {
          "Name": "ImageId",
          "Selector": "$.LaunchTemplateVersions[0].LaunchTemplateData.ImageId",
          "Type": "String"
        }
      ]
    },
    {
      "name": "updateWindowsAmi",
      "action": "aws:executeAutomation",
      "inputs": {
        "DocumentName": "AWS-UpdateWindowsAmi",
        "RuntimeParameters": {
          "SourceAmiId": "{{ getLaunchTemplate.ImageId }}",
          "IamInstanceProfileName": "ManagedInstanceProfile",
          "AutomationAssumeRole": "arn:aws:iam::{{global:ACCOUNT_ID}}:role/AutomationServiceRole",
          "TargetAmiName": "{{ TargetAmiName }}"
        }
      }
    },
    {
      "name": "createTemplateVersion",
      "action": "aws:executeAwsApi",
      "inputs": {
        "Service": "ec2",
        "Api": "CreateLaunchTemplateVersion",
        "LaunchTemplateId": "{{ LaunchTemplateId }}",
        "SourceVersion": "{{ getLaunchTemplate.Version }}",
        "LaunchTemplateData": {
          "ImageId": "{{ updateWindowsAmi.Output }}"
        }
      }
    }
  ]
}