This may not be the only way to get there -- it seems rather cumbersome to have to go through all this to change settings -- but I am rather new to this myself and still learning.
In the
smart controller, when you have the drone powered up and connected to the controller and are in the DJI Fly app - where you can actually launch the drone - there is a three dot icon top right corner. Tapping that icon brings up the major drone menus, one of the tabs is for the camera system. The settings are pretty clear - but you have choices for 4k 30Hz, 4k 60Hz, 1080, 2.4k etc. And then format choices, MP4, MOV, H265, D-Cine or normal, Wide or Zoom, and more. The drone has to be running because that is where you are setting the camera up. Once you've made your selection, you can return to the fly app and click the record button to capture a short clip - power the drone down and pop out the SD card to see what you actually recorded.
Also - the system can store video on the controller, basically a running screen shot of the flight - this is HD at best.
ps: I like the post above mine - he posted his just as I was finishing up my typing. Much simpler to get to video - but the three dots top right are where all the other settings are..