AWS API Gateway与Lambda配置CORS后仍报错问题咨询

我使用AWS API Gateway和Lambda搭建API服务，前端发起请求时遭遇CORS跨域拦截。检查配置时发现：尽管已在API Gateway中为所有方法启用CORS，但Lambda触发器配置区域内，对应API Gateway端点的CORS字段显示为NO。

现有配置详情 #

API Gateway CORS配置 #

[API Gateway CORS配置截图]

Lambda 响应头中的CORS配置代码 #

export const handler = async (event, context) => {
  let body;
  let response;
  let statusCode = 200;
  const headers = {
    "Access-Control-Allow-Origin": "https://www.yoteinvito.com",
    "Access-Control-Allow-Headers": "Content-Type, Accept",
    "Access-Control-Allow-Methods": "POST, GET, PUT, OPTIONS",
    "Access-Control-Allow-Credentials":"true",
  };

Lambda触发器配置 #

[Lambda触发器配置页面]

前端请求头配置 #

headers: {
  'Content-Type': 'application/json',
},
body: JSON.stringify(formData),  
})

浏览器控制台错误信息 #

Access to fetch at 'https://rgfz15v2qp.execute-api.us-east-2.amazonaws.com/dev/confirmations' from origin 'https://www.yoteinvito.com' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

疑问与求助 #

我已在API Gateway中为所有方法（GET、POST、PUT、DELETE等）启用CORS，添加了必要响应头并配置了OPTIONS请求的响应规则，但仍出现上述跨域错误。想咨询：

1. API Gateway端点详情中显示CORS: NO是否属于正常情况？
2. 该显示是否是导致CORS报错的直接原因？
3. 还需执行哪些操作才能确保CORS完全生效？

内容的提问来源于stack exchange，提问作者Angel Hernadez