Backblaze B2 Cloud Storage provides an S3-compatible API, allowing applications designed for Amazon S3 to work with B2 storage.

Backblaze B2 Cloud Storage Now Has S3 Compatible APIs

KLS Backup supports both the native Backblaze B2 API and the S3-compatible API. Use the S3 Compatible Storage Account dialog to set up the connection.

The S3-Compatible API supports only v4 signatures for authentication. The S3-Compatible API endpoints accept connections only over HTTPS. Use your Backblaze B2 Application Key and keyID as the S3 Secret Key and Access Key, respectively.

Use the Endpoint displayed in your bucket properties as the S3 service URL.