解决vue2中使用axios http请求出现的问题

Uncaught (in promise) Error: Request failed with status code 404

var instance = axios.create({
 headers: {'content-type': 'application/x--form-urlencoded'}
});
instance .post(`url`, params).then(res => res.data);

var qs=require('qs');
var instance = axios.create({
 headers: {'content-type': 'application/x--form-urlencoded'}
});
instance .post(`url`, qs.stringify(params)).then(res => res.data);