So the issue for me was solved once I started to use bucket name instead of bucket id. The latter was mentioned in online docs here: https://www.backblaze.com/

So the issue for me was solved once I started to use bucket name instead of bucket id. The latter was mentioned in online docs here: https://www.backblaze.com/b2/docs/quick_command_line.html https://www.backblaze.com/b2/docs/quick_command_line.html but seems it's REALLY outdated.