Yes, it is possible to disable the ability to invite new users by email in QuickSight using the AWS Command Line Interface (CLI) or the AWS SDK. To do this, you will need to use the UpdateAccountCustomization operation in the QuickSight API.

Here is an example of how you can use the AWS CLI to disable the ability to invite new users by email in QuickSight:

aws quicksight update-account-customization \
  --aws-account-id 123456789012 \
  --namespace default \
  --account-customization '{"enableInviteNewUsersByEmail":false}'

In the example above, you would need to replace '123456789012' with the actual AWS account ID for your QuickSight account, and 'default' with the namespace that you want to update. You can also specify additional settings in the account-customization parameter, such as the default email sender name and address.

Alternatively, you can use the AWS SDK to call the UpdateAccountCustomization operation in the QuickSight API directly, as shown in the following example:

# Import the AWS SDK
import boto3

Create a QuickSight client

quicksight = boto3.client('quicksight')

Update the account customization settings

response = quicksight.update_account_customization(
  AwsAccountId='123456789012',
  Namespace='default',
  AccountCustomization={
    'EnableInviteNewUsersByEmail': False
  }
)

I hope this helps! Let me know if you have any other questions.