Casa2G 90 - countertoppable?

[Yuggs]

After years of research, this is my first post (thanks for the dreams!). I've been a casual sourdough pizza and bread baker for the past ~8yrs, and I finally got permission from SWMBO to get a masonry oven for our outdoor patio in the new home we're building.

I'm planning on installing an "L" shaped outdoor countertop with sink and grill, and placing the oven in the corner part of the "L". For the oven, I've settled on a 36" Casa2G or a pre-assembled Toscana 90.

My question is: can I just install the oven right on top of the granite countertop? or do I need to build a concrete hearth base?

Thanks in advance.