问题可能出现在 AccessPolicy 中。检查 AccessPolicy 中的 PolicyDocument，"Effect" 和 "Action" 是否正确，并确保 "Resource" 引用了正确的资源 ARN。此外，还需确保 Cognito 身份池 ID、用户池 ID 和角色名称均正确。

示例代码：

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "es:*"
      ],
      "Resource": "arn:aws:es:us-west-2:123456789012:domain/my-domain/*",
      "Condition": {
        "Bool": {
          "aws:SecureTransport": "true"
        }
      }
    },
    {
      "Effect": "Allow",
      "Action": [
        "cognito-identity:*"
      ],
      "Resource": [
        "arn:aws:cognito-identity:us-west-2:123456789012:identitypool/us-west-2:11111111-2222-3333-4444-555555555555",
        "arn:aws:cognito-idp:us-west-2:123456789012:userpool/us-west-2_abcdefghi",
        "arn:aws:iam::123456789012:role/Cognito-MyTestRole"
      ]
    }
  ]
}