I ran into this recently. Firefox has a "packager" for putting together add-ons. It uses "node.js". All it really does is apply "zip" to some files. I tried to install the "packager" on Ubuntu 18.04 LTS. It had several hundred dependencies, and wouldn't run because of some version dependency in node.js for something totally irrelevant to the task at hand. Mozilla support suggested upgrading the operating system on the development machine.
I wrote a one-line shell script which zipped up the proper file types into one file to package the add-on.