I would call and explain, if it’s a technical issue. Last year, I accidentally submitted a completely blank secondary to my top choice. I freaked out and called the school after 2 minutes (sobbed for 90 seconds thinking my life was over, followed by 30 seconds of ‘oh s***, now how do I fix this?’) and explained the mistake, fully acknowledging that I made a mistake. They let me email my secondary. I will now be attending this school.
Obviously, it’s not the same, this is your primary, but I think it’s worth calling even if it draws attention to it. Technical issues do happen, humans and computers don’t always work together smoothly.
Now if the essay’s narrative doesn’t suffer, move on and congratulate yourself on finishing your primary.