You need to download the file and upload it into a software (such as the p5.js website).
It doesn't run directly on itch.io.
Thank you!
Thank you for your help. I uploaded the zip and removed the github.
I had school so I didn't have time, but since we got out I fixed it. Can you let me know if it works, this is my first time using itch.io so if it doesn't, feedback how to fix this would be very helpful. Thank you.