Putting wrong grades into an application

I’m not certain but I might of accidentally put the wrong grade for my gcse science grade by one grade on my ucas application. What can I dk to prevent any punishment. I only sent my application 2 days ago

Hi! I made a similar mistake, I put the wrong title down for one of my qualifications, but it is easily fixable! Just fill in this form: https://www.ucas.com/applying/after-you-apply/making-changes-to-your-application-after-you-apply#changes-to-exams-and-qualifications
It is also recommendable to email the unis to clarify, my UCAS officer did this for us, the unis came back and were very chill about it and there won't be any punishment.
She also recommended that WE also send them an email just for insurance but that it wouldn't be necessary (but I think this was only because she had already emailed them so I'd suggest you do email them), this is the template she gave us for the email:
Full name:​

Please let me know if there is anything else I need to do.​

Hi, thanks so much for that should I fill in a send this form now and send an email or wait for anything in particular because there’s mixed answers on Google.

Complete the form then send an email to your uni choices a day or two later.

Hi, thanks so much for that should I fill in a send this form now and send an email or wait for anything in particular because there’s mixed answers on Google.

You think I should complete the form as soon as possible?

Hi, thanks so much for that should I fill in a send this form now and send an email or wait for anything in particular because there’s mixed answers on Google.

Have you checked to see if you did actually make a mistake? Schools should be checking the grades you entered.