Not able to connect to my rds cluster using PG admin

I have created my RDS cluster using CFT.

This is the CFT which I used

{
    "AWSTemplateFormatVersion": "2010-09-09",
    "Description": "The template for aurora rds cluster.",
    "Parameters": {
      "tagName": {
        "Type": "String"
      },
      "subnetIds": {
        "Type": "CommaDelimitedList"
      }
    },
    "Resources": {
      "dbSubnetgroup": {
        "Type" : "AWS::RDS::DBSubnetGroup",
        "Properties" : {
            "DBSubnetGroupDescription": "DB subnet group of aurora",
            "SubnetIds" : {
              "Ref": "subnetIds"
            },
            "DBSubnetGroupName" : {
              "Fn::Sub": "${tagName}-subnetGroup"
            },
            "Tags" : [ {
              "Key" : "service",
              "Value" : {
                "Ref": "tagName"
              }
            } ]
          }
      },
      "rdsCluster": {
        "Type": "AWS::RDS::DBCluster",
        "Properties": {
          "MasterUsername": { "Ref": "dbUsername" },
          "MasterUserPassword": { "Ref": "dbPassword" },
          "DBClusterIdentifier": {
            "Fn::Sub": "${tagName}"
          },
          "Engine": "aurora-postgresql",
          "DBSubnetGroupName": {
            "Fn::Sub": "${tagName}-subnetGroup"
          },
          "EnableCloudwatchLogsExports": ["postgresql"],
          "EnableHttpEndpoint": true,
          "Port": 5432,
          "Tags" : [ {
            "Key" : "service",
            "Value" : {
              "Ref": "tagName"
            }
          } ]
        },
        "DependsOn": [
          "dbSubnetgroup"
        ]
      }
    },
    "Outputs": {
      "clusterEndpoint": {
        "Description": "The RDS Cluster endpoint",
        "Value": {
          "Fn::GetAtt": [
            "rdsCluster",
            "Endpoint.Address"
          ]
        }
      }
    }
  }

I am not able to connect with the PG admin, its giving timeout

is there any specific permission requirements?? Thank you in advance