如何在页面加载后使用javascript修改html

我是js新手，正在学习如何使用js修改html，我想修改：

<video controls="" controlslist="download" src="//storage.googleapis.com/media-session/caminandes/short.mp4#t=80">&lt;</video>

到

页面加载后，我想将controlslist=download更改为controlslist=nodownload

页面src:

使用如下所示的onload事件

window.onload = function() {

    // select your expected video tag 
    // change attribute controlslist value to expected one 

}

完整代码：

window.onload = function() {
    // select your expected video tag 
    // change attribute controlslist value to expected one 
    var searchString = "t=80";
    var videos = document.getElementsByTagName("video");
    for (let item of videos) {
        if (item.getAttribute("src").includes(searchString)) {
            item.setAttribute("controlslist", "Anything I want")
        }
    }
}

---

正如你在src看到的，有多个元素，所以我不能选择src，所以你可以发布修改后的代码src:：@elite谢谢你的解释，添加了完整的代码。别忘了投票并接受答案。

window.onload = function() {
    // select your expected video tag 
    // change attribute controlslist value to expected one 
    var searchString = "t=80";
    var videos = document.getElementsByTagName("video");
    for (let item of videos) {
        if (item.getAttribute("src").includes(searchString)) {
            item.setAttribute("controlslist", "Anything I want")
        }
    }
}