how to change the default video codec in screenrecordings on an iMac with Sequoia?

Explanations say Choose New Screen Recording in Quicktime Player, then Use the Arrow next to the record button to get to Settings. For me this arrow brings up Options, none of which allow access to the default video codec, which is H264

I find the default codec creates such large files, and although it's possible to then change the codec in a separate app, it all takes such a long time.