I had contacted support of Ninja Trader, and they told me I would have to purchase the lifetime license to access the volumetric bars. I think, the chart you linked is different from volumetric bars.
My ultimate goal is to go through a funded trader program, to get a funded account. Before I pay for their monthly fees, I want to learn and practice trading on my own. I want to use Foot Print Charts, like the image below, but I don't know where to find such charts for the lowest possible cost...