Heya,
That program was probably Inkscape?
Although any decent SVG editor will work.
In the SVG file you need to define the shapes of your map (including territories and bonus boxes).
The SVG file then gets uploaded to Warzone where in the Map Designer you assign what territory belongs to which bonuses and what the value of the bonuses should be.
Details on what object ids the territories and bonus boxes need to have for Warzone to recognize them can be find on the wiki:
https://www.warzone.com/wiki/Creating_the_SVG.
I highly recommend you join the map makers Discord:
https://discord.gg/CeaHVqWP.
