Why I can't search on WhatsApp web with this JavaScript code?

let xPath = "/html/body/div[1]/div[1]/div[1]/div[3]/div/div[1]/div/label/div/div[2]";
let result = document.evaluate(xPath, document);
let searchBox = result.iterateNext();
searchBox.innerText='my contact name'

It just shows my contact name in search box but it's not filter my contact. How can I filter my contact after I enter my contact name in the search box?