Who creates a HTTP request? code example

Example 1: what is http request made of

1-Http request methods : PUT, POST, DELETE,GET
2-Base URI
3-Resources and Parameters
4-Request Header(which carries metaData)as keyValue pair
5-Request Body

Example 2: create http request

const xhr = new XMLHttpRequest();

let method = 'GET';
let endpoint = 'what you looking for';

xhr.open(method, endpoint);
xhr.send();

xhr.onload = () => {
	'working what you get'
};