Creating a stackset with cloudformation TO DEPLOY STACK IN MY MEMBERS ACCOUNT

Hello, Pls i need help with sample cloudformation code on how to deploy a stack set with cloudformation i keep getinng this error below, will really appreciate a correct code and the reason i was haveing error and what i was getting wrong

ERROR Properties validation failed for resource TestingStackSet20240411 with message: #: #: only 1 subschema matches out of 2 #/StackInstancesGroup/0: required key [DeploymentTargets] not found #/StackInstancesGroup/0: required key [Regions] not found #/StackInstancesGroup/0: extraneous key [StackInstances] is not permitted

CODE

  TestingStackSet20240411:
    Type: AWS::CloudFormation::StackSet
    Properties:
      StackSetName: TestingStackSet20240411
      TemplateURL: https://s3.amazonaws.com/<your-bucket>/StackSetTemplate.yaml
      Parameters:
      - {ParameterKey: BucketName, ParameterValue: TestingBucketName}
      # Tags: #[Array of Tag]
      Capabilities: #[Array of String]
      - CAPABILITY_NAMED_IAM
      PermissionModel: SELF_MANAGED #Allowed Values[SERVICE_MANAGED | SELF_MANAGED]
      AutoDeployment:
        # Describes whether StackSets automatically deploys to AWS Organizations accounts that are added to a target organizational unit
        Enabled: false
        RetainStacksOnAccountRemoval: false
      # StackInstancesGroup: #[Array of StackInstances]
      StackInstances:
      - DeploymentTargets:
          # AccountFilterType: #Allowed Values[NONE | UNION | INTERSECTION | DIFFERENCE]
          # OrganizationalUnitIds: #[Array of String]
          # AccountsUrl: [String]
          Accounts: #[Array of String]
          - !GetAtt TestingOUAccount20240411.AccountId #!RefTestingOUAccount20240411
          Regions: #[Array of String]
          - us-east-1
        ParameterOverrides: #[Array of Parameter]
        - {ParameterKey: BucketName, ParameterValue: TestingBucketName,}