Backup and restore a managed ELK to Azure Blob

We have a managed ELK instance on elastic.co with URL similar to:

randomname.us-central1.gcp.cloud..io:9243

The instance is fully managed by Elastic and we dont have a server access.
We want to backup the indexes to an Azure Blob storage, but unfortunately all the documentation refers to how to do that if you manage the instance yourself (i.e. your own setup) and not how to do this from elastic.co account.

For instance, the following document details steps that does NOT exist in elastic.co account and is applicable if you have full control over your own setup (i.e. your own installation on a cloud service provider):

Configure a snapshot repository using Azure Blob storage | Elasticsearch Service Documentation | Elastic

Please note that we have large indexes and thus doing this using elasticdump for instance will be a heavy task and might fail as well.

Your support would be highly appreciated.
Thank you