[TOC] ## 上传 JSON 数据 ``` const data = { username: 'example' }; fetch('https://example.com/profile', { method: 'POST', // or 'PUT' headers: { 'Content-Type': 'application/json', }, body: JSON.stringify(data), }) .then(response => response.json()) .then(data => { console.log('Success:', data); }) .catch((error) => { console.error('Error:', error); }); ```