How to add a program in MX using Terminal

[UNCNDL1]

I wanted to add a program using MX 18.2 that is not in the Synaptic Package Manager.
The example used is a program called Etcher: https://www.balena.io/etcher/
This program is a cross-platform tool for flashing images to SD cards & USB drives.
"It's a powerful OS image flasher built with web technologies to ensure flashing an SDCard or USB drive is a pleasant and safe experience. It protects you from accidentally writing to your hard-drives, ensures every byte of data was written correctly and much more." (description in Synaptic)
This MX forum post explains how to do it, which I copied and pasted in Terminal:
https://forum.mxlinux.org/viewtopic.php?f=55&p=501988
I'll have to report back after using the program but here's a screenshot of the Terminal commands:

[UNCNDL1]

Here's what your screen will look like when opening the Etcher program: