The top "cam" that operates the throttle butterfly and which is usually integral with the throttle shaft (pressed together) is gone. This is leaving you with nothing to attach the throttle cable to. Where it goes is in the vertical hole in the middle of the carb.
Your cable can attach directly to the throttle butterfly or to whatever throttle/governor linkages ran along the side of the carb, which also appear to be missing.
EDIT--or maybe it's there. The carb looks so corroded and covered with what looks like green verdigris, that I cannot tell what I'm looking at. :doah: