Note: As an unsupported destination - we do NOT recommend using Backblaze B2 as a destination and will no longer provide any technical support for issues that directly involves Backblaze B2. For more information, please refer to our knowledgebase article.
Backblaze default lifecycle configuration will keep all versions of the same file. This should be set to "Keep only last version" to prevent excess storage usage.
When not using master application keys, the application key must have all privileges (Read and Write) on the targeted bucket.