Check out the link to read about Backblaze now supporting S3.

This means that you can now use Hyper Backup with Backblaze B2, here is a setup guide.

https://help.backblaze.com/hc/en-us/articles/360047171594-How-to-use-Synology-Hyper-Backup-with-B2

When you create the application key make sure you set this option to your specific bucket:

"Allow access to Bucket(s):"

and ticket this option:

"Allow List All Bucket Names: Allow listing all bucket names including bucket creation dates (required for S3 List Buckets API)"

Article:

https://www.backblaze.com/blog/backblaze-b2-s3-compatible-api/