Give k3b the ability to write to optical disk always:
----------------------------------------------------- 
sudo chmod 4711 /usr/bin/wodim; sudo chmod 4711 /usr/bin/cdrdao

This will set the UID bit on the necessary binaries. It is illustrated in Settings -> Configure k3b -> programs -> Permissions "tab".

from: https://askubuntu.com/questions/1032903/problem-with-k3b-in-18-04-releases-cdrecord-has-no-permission-to-open-the-devi

Origonal Creation date in Vivaldi: 25 June 2018 @ 23:16