Option to import themes previously exported from VSLook

I want to let my friend copy my theme, but there is no import option. I tried just replacing manually the index.json file that has the current color settings with the exported file and it works, but then when I close VSCode the file gets reset to how it was before, and I don't know what else I need to change. It would be better if there was an actual built-in option to import a theme from a file.