I have no knowledge of the software, and have no ability to answer. However, if I run this command I do see some software which could be installed: apt search bossac
What it shows is:
bossa-cli/bionic 1.3~20120408-5.1 arm64
Atmel SAM ARM microcontroller flash programming utility
So perhaps if this software is what is missing, then you might be able to install via:
sudo apt-get install bossa-cli
I have no idea if this would help or not, but it might be worth researching.