How to delete an update files

Hello,

I am currently running mac OS Mojave.

Suddenly I got the notification that there is a new update to OS Catalina.

I don't want to update but it seems that the update files have been already downloaded to my computer because it says that I am running out of space.

I already ticked off the option in Software Updates so it will no longer download the updates automatically.

Do you know where can I find the files with the update and delete them?

Thank you