How to save the design to FLASH with an Arty A7-35T

I've been exploring and learning about FPGAs with this board and its very interesting. I know the board has FLASH but I can't really make sense of how to leverage this. In Vivado I can "Program Device" after generating the bitstream but can't see how I can send the code to FLASH rather than volatile memory.

I've assumed this is simple, perhaps a jumper or some setting in Vivado or in my project but it's just not making sense and seems that it might be quite involved.

Any help appreciated.