JSFiddle - React, Tailwind, and code Playground

JavaScript

function getUniques(min, max, n){
    n = n || 1;
    if(n > max-min+1 || n < 0) return [];
    var t = [];
    for(var i = 0; i < n; i++){
        var a = Math.floor(min + Math.random() * (max + 1 - min));
        if(t[a]) i--;
        t[a] = 1;
    }
    var ret = [];
    for(i in t) ret[ret.length] = ~~i;
    return ret;
}

document.write(getUniques(0, 3, 3));