为什么我无法从Amazon S3获得“签名网址”？

Question

我想使用 Nodejs 从 Amazon s3 获取Signed Url，构建存储桶和IAM，但是在使用邮递员从计算机发送请求后，我总是得到回应说：

concurrency

这是我的nodejs代码：

"e": {
        "message": "Missing credentials in config",
        "errno": "ETIMEDOUT",
        "code": "CredentialsError",
        "syscall": "connect",
        "address": "169.251.165.251",
        "port": 80,
        "time": "2018-08-04T17:20:32.554Z",
        "originalError": {
            "message": "Could not load credentials from any providers",
            "errno": "ETIMEDOUT",
            "code": "CredentialsError",
            "syscall": "connect",
            "address": "169.251.165.251",
            "port": 80,
            "time": "2018-08-04T17:20:32.554Z",
            "originalError": {
                "errno": "ETIMEDOUT",
                "code": "ETIMEDOUT",
                "syscall": "connect",
                "address": "169.251.165.251",
                "port": 80,
                "message": "connect ETIMEDOUT 169.251.165.251:80"
            }
        }
    }