SOURCE

const aaa = (num) => {
    if (num > 10 ** 3) {
        const arr=num.toString().split('.');
        let num1=arr[0].split(''),i=num1.length-3;
        while(i>0){
            num1.splice(i,0,'-')
            i-=3
        }
        num1=num1.join('')
        arr[1]&&(num1 += '.'+arr[1]);
        return num1.replaceAll('-',',')
    }
}
console.log(aaa(1036926001.01))