Пример запроса на узел.
let todo = {
userId: 123,
title: "loren impsum doloris",
completed: false
};
fetch('https://jsonplaceholder.typicode.com/todos', {
method: 'POST',
body: JSON.stringify(todo),
headers: { 'Content-Type': 'application/json' }
}).then(res => res.json())
.then(json => console.log(json));
AttractivePenguin