You can get the sessions using public REST API for that. You can check this particular script (it builds report for 1 day, but you can change it to any other period of time) https://github.com/VeeamHub/veeam-nutan ... _report.py
But please be aware that by default the appliance stores the sessions data for the last 13 weeks (91 days). It is possible to change the sessions retention period in appsettings.json file on the appliance.
To change it:
Enable ssh
Connect to hte machine via ssh
navigate to /opt/VeeamBackupAgent/appsettings.json
Change "SessionRetention" parameter to the desired value (in days).
Restart service: sudo service VeeamBackupAgent restart