Your sumo is pretty bad the timing is off. You are not coming tight enough to your body. You are leaning over and using your upper body to muscle it up.
As mentioned keep your back neutral this is most important, you are rounding too much. Bring the bar tight to your body as possible. You want to think more so of leg drive lean back hip thrust. Your shoulders are out of synch with your hips,Try to get your ass lower and initialize the lift with maximal leg drive keep your back straight as possible, hip thrust+ victory. Get lower for you sumo especially
Bar over your heels or middle point of your feet. I feel that your hips and shoulders should be moving towars the ending at the same rate and not one way before the other just my opinion.