Show backup sizes on recovery points and long term MSSQL backups

This is a follow up of this issue below, but I was told to come here instead:
https://github.com/Azure/azure-sdk-for-python/issues/20910

I want to know the size of recovery point of backups items that you can find here:
https://portal.azure.com/#blade/HubsExtension/BrowseResource/resourceType/Microsoft.RecoveryServices%2Fvaults%2FbackupFabrics%2FprotectionContainers%2FprotectedItems

In the same sense I would like to know the backup size of long term retention of SQL Server instances:
https://portal.azure.com/#@REDACTED/resource/subscriptions/REDACTED/resourceGroups/test/providers/Microsoft.Sql/servers/mssqldb-server/longTermRetentionV2 (I redacted my account names from this)

We want to be able to analyze the backups we have and see which ones can be dropped. I am fetching data with the SDK

Regards,

Start by reviewing the linked Azure SDK issue 20910 and the REST API specifications for Recovery Services recovery points and SQL Server long-term retention. Done means the relevant API descriptions expose backup or recovery-point sizes for both requested areas.

Written by the indexing model from the issue text.