How to create an unique and random number from an array in Javascript

i'm a super beginner in JS. I try to create a way to generate random unique number (between 0 and 10) by clicking on a button. I want that this number is delete from the array after appearing.

Thank you 🙏🏻

const btn = document.getElementById("btn");

const showNumber = document.querySelector("h2");


let allNumbers = [];
for (var i =1; i <= 10; i++){  
    allNumbers.push(i);
}


const randomNumber = btn.addEventListener('click',()=> {
  let n = Math.floor(Math.random()*allNumbers.length+1);
  showNumber.innerText = n;

 });



 if(allNumbers.indexOf(n+1) === n) {  
    allNumbers.splice(n-1,1);
};