SHA256SUMS for the ISO:

c1c21250a69953bb1132123f8ffcfd37627e2ac46130fa027de154178e32017f

Release notes

23. November 2021: Proxmox Backup Server 2.1 ISO Installer (1st ISO release)
13. July 2021: Proxmox Backup Server 2.0 ISO Installer (1st ISO release)
15. April 2021: Proxmox Backup Server 1.1 ISO Installer (1st ISO release)
11. November 2020: Proxmox Backup Server 1.0 ISO Installer (1st ISO release)
5. October 2020: Proxmox Backup Server beta ISO Installer (2nd ISO release)
10. July 2020: Proxmox Backup Server beta ISO Installer (1st ISO release)

Note: Please always update a new ISO install to the latest available packages via GUI updater or via CLI (apt update && apt  dist-upgrade)