How to dedupe pair of random numbers in JavaScript

I have a function that generates random numbers given a range I want to make sure I don't re-generate the same pair of numbers.

   function generateRandomInt(max) {
          return Math.floor(Math.random() * Math.floor(max));
    }

    let randomInt1 = generateRandomInt(10) + 1;
    let randomInt2 = generateRandomInt(10) + 1;

    let numberStore = randomInt1 + "" + randomInt2; 

console.log(randomInt1);
console.log(randomInt2);
console.log(parseInt(numberStore));

numberStore contains the result of randomInt1 and randomInt2 I want to avoid having a pair of numbers that were already generated.

https://codepen.io/anon/pen/wRJrrW