How to do what youtube chanel 'military summary' does?

I’ve been following the Ukraine thing and there’s a youtube chanel called ‘military summery’ that I think uses openstretmaps - at least that’s the name in the bottom right corner of his screens.

And he draws on the map and has shaded portions and I think puts icons on it or whatever. Anyway, he plays with it, uses it to good effect. I would like to do the same. Anyone got any idea of how I could do that?

Perhaps with something like ?