How to make button desappear?

Hi y’all! I’ve got a very urgent question and I appreciate your help! So please answer!
How can I let the red button “start new game” desappear when something got saved over prefabs. See attachment.
thank you very much. Lomusire

6167291--674708--Anmerkung 2020-08-04 133839.png

.gameObject.SetActive(false)