TraceyC ℹ Moderator Note I've split this off into a new thread, since it's not directly related to the solved question from the other topic. We request that in Support, users stick to one topic per thread and create new threads for different issues. This keeps questions and solutions clear, both for you and for other members of the forum. Thanks.
stocc efibootmgr is the command you want, I think. sudo eopkg it efibootmgr if it's not already installed.