The module azure_rm_virtualmachine has fields for plan information. Module azure_rm_virtualmachinescaleset needs to have them and forward them when creating a VM with an image that requires plan info to be specified. The CIS hardened images from the Azure Marketplace is a prime example.

- Standard
    upgrade_policy:
        description:
            - Upgrade policy.
            - Required when creating the Azure virtual machine scale sets.
        choices:
            - Manual
            - Automatic
    admin_username:
        description:
            - Admin username used to access the host after it is created. Required when creating a VM.
    admin_password:
        description:
            - Password for the admin username.
            - Not required if the os_type is Linux and SSH password authentication is disabled by setting I(ssh_password_enabled=false).
    ssh_password_enabled:
        description:
            - When the os_type is Linux, setting I(ssh_password_enabled=false) will disable SSH password authentication and require use of SSH keys.
        type: bool
        default: true
    ssh_public_keys:
        description:
            - For I(os_type=Linux) provide a list of SSH keys.
            - Each item in the list should be a dictionary where the dictionary contains two keys, C(path) and C(key_data).
            - Set the C(path) to the default location of the authorized_keys files.
            - On an Enterprise Linux host, for example, the I(path=/home/<admin username>/.ssh/authorized_keys).
              Set C(key_data) to the actual value of the public key.
    image:
        description:
            - Specifies the image used to build the VM.