Please enable "Custom Domain for AppStream 2.0 Stacks” feature in eu-west-2

To use custom domains with Amazon AppStream 2.0, you have a couple of options available to you currently:

1. You can configure custom domains by using Amazon CloudFront as a reverse proxy in front of your AppStream 2.0 environment. This allows you to display a company URL instead of an AppStream 2.0 URL to your users.

2. For embedding AppStream 2.0 streaming sessions in a webpage, you need to specify authorized host domains. This is done by updating your stack to specify which domains are allowed to host embedded streaming sessions. You can do this through:

• The AppStream 2.0 console
• The EmbedHostDomains API action
• The embed-host-domains AWS CLI command

Regarding your specific request about enabling a "Custom Domain for AppStream 2.0 Stacks" feature in eu-west-2 region, I don't see information in the available documentation that indicates this is a feature that needs to be enabled for your account. The --custom-domain-config parameter you mentioned doesn't appear to be part of the current AppStream 2.0 CLI documentation.

If you're looking to use custom domains with AppStream 2.0, I recommend exploring the CloudFront integration option mentioned above, or if you're trying to embed AppStream 2.0 sessions, use the embed host domains functionality.
Sources
Prerequisites for Embedding Amazon AppStream 2.0 Streaming Sessions - Amazon AppStream 2.0
Step 1: Specify a Host Domain to Embedded Amazon AppStream 2.0 Streaming Sessions - Amazon AppStream 2.0

Thanks, we'll look into the Cloudfront method.