querySelectorAll can be used to target multiple selectors.

document.querySelectorAll("#div1, .div2, h3");

The querySelector() method returns the first element that matches a specified CSS selector(s) in the document.

Keep in mind that to return all the matches, use the querySelectorAll() method instead.

example

<div class="bar">.first </div>
<div class="bar">.second</div>
    
//get the first element with class bar
let firstElement = document.querySelector('.bar');
//log the first match
console.log(firstElement)

//get all elements with class bar
let allElements = document.querySelectorAll('.bar')
//You can use any common looping statement to access the matches
allElements.forEach(function(elements){
console.log(elements);
});
    /*
    querySelector("#ID1, #ID2, ID#3") 
    
    *select element matches #ID1 
    *select element matches #ID2
    *select element matches #ID3
    
    **/
//select  elements matches specified selectors #id1 , #id2 , #id3 and use any common looping statement to access them
let allMatchesId = document.querySelectorAll('#id1 , #id2 , #id3');
allMatchesId .forEach(function(elements){
console.log(elements);
});

read the docs here at MDN https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelectorAll

Simple ! Use following code.

document.querySelectorAll('#id1, #id2 , #id3');

This will return nodelist which you can iterate and can perform actions that you want.