有兩個錯誤Uncaught (in promise) TypeError: Failed to fetchFailed to load 'url鏈接' Request header field Content-Type is not allowed by Access-Control-Allow-Headers in preflight response.這是代碼url那里我原來放的是后臺給的地址fetch('url',{ method: 'POST', headers: {           'Accept': 'application/json',            'Content-Type': 'application/json'          },          body: JSON.stringify({"password": values.password})}).then(res => res.json()).then(json => console.log(json));