使用获取发出POST请求

 var headers = {
   "Content-Type": "application/json",                                                                                                
   "Access-Control-Origin": "*"
}

尝试将上述行添加到标题中。

var data = {
    "email": "peter@klaven",
    "password": "cityslicka"
}

fetch("https://reqres.in/api/login", {
    method: "POST",
    headers: headers,
    body:  JSON.stringify(data)
})
.then(function(response){ 
    return response.json(); 
})
.then(function(data){ 
    console.log(data)
});