Create a Game Start button

Click the + button in the upper left -> GUI -> Select the start button you want

Select Start Button

otherScript

const startbtn = GUI.getObject("ballstopcle_button_play_on(e77)");
 
function Start() {
  startbtn.onClick(() => {
    startbtn.hide();
  });
}

If the script above is part of a start button script, it could be written as follows:

ballstopcle_button_play_on(e77)

function Start() {
  this.onClick(() => {
    this.hide();
  });
}