The tool you are looking for is /Library/Backblaze.bzpkg/bztransmit and if you run it without any arguments to see all of its options.
Disable
These three commands can be used to stop Backblaze:
sudo launchctl stop com.backblaze.bzbmenu
sudo launchctl unload /Library/LaunchDaemons/com.backblaze.bzserv.plist
/Library/Backblaze.bzpkg/bztransmit -pausebackup
The first two are basically doing the same thing - telling launchd to stop the process. That will stop Backblaze until you start it again (see below) or reboot.
The third one will pause Backblaze for some period of time, I think 4 hours.
Enable
These two commands will re-enable Backblaze if you have used the opposite commands shown above:
sudo launchctl stop com.backblaze.bzbmenu
sudo launchctl load /Library/LaunchDaemons/com.backblaze.bzserv.plist
This one is suppose to “start” a backup.
/Library/Backblaze.bzpkg/bztransmit -completesync
The most reliable way to stop Backblaze is the launchd way but if you want to automate it you may need to add the commands to sudoers file.
Hope that helps. Let me know if you have more questions.