要获取ElasticBeanstalk环境的负载均衡器ARN以供ApiGateway VPC链接使用，您可以使用AWS CDK来完成。下面是一个使用TypeScript编写的示例代码：

import * as cdk from 'aws-cdk-lib';
import { Construct } from 'constructs';
import * as elasticbeanstalk from 'aws-cdk-lib/aws-elasticbeanstalk';
import * as apigateway from 'aws-cdk-lib/aws-apigateway';
import * as ec2 from 'aws-cdk-lib/aws-ec2';

class MyStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    // 创建VPC
    const vpc = new ec2.Vpc(this, 'MyVpc', {
      // 添加所需的VPC配置
    });

    // 创建ElasticBeanstalk环境
    const ebsEnvironment = new elasticbeanstalk.CfnEnvironment(this, 'MyEbsEnvironment', {
      // 添加所需的ElasticBeanstalk环境配置
    });

    // 获取ElasticBeanstalk环境的负载均衡器ARN
    const ebsEnvironmentArn = `arn:aws:elasticbeanstalk:${this.region}:${this.account}:environment/${ebsEnvironment.ref}`;

    // 创建ApiGateway
    const api = new apigateway.RestApi(this, 'MyApi', {
      // 添加所需的ApiGateway配置
    });

    // 创建VpcLink并将其与ApiGateway关联
    const vpcLink = new apigateway.VpcLink(this, 'MyVpcLink', {
      targets: [ec2.Vpc.fromVpcAttributes(this, 'Vpc', {
        vpcId: vpc.vpcId,
        availabilityZones: vpc.availabilityZones,
        publicSubnetIds: vpc.publicSubnets.map(subnet => subnet.subnetId),
        privateSubnetIds: vpc.privateSubnets.map(subnet => subnet.subnetId)
      })]
    });
    api.addVpcLink(vpcLink);

    // 创建Integration并将其与ApiGateway关联
    const integration = new apigateway.AwsIntegration({
      service: 'elasticbeanstalk',
      integrationHttpMethod: 'POST',
      options: {
        credentialsRole: iamRole.roleArn,
        integrationResponses: [
          // 添加所需的Integration Response配置
        ],
        requestTemplates: {
          'application/json': `{
            "elasticbeanstalk": {
              "EndpointURL": "${ebsEnvironmentArn}"
            }
          }`
        }
      }
    });

    const resource = api.root.addResource('example');
    resource.addMethod('POST', integration);
  }
}

const app = new cdk.App();
new MyStack(app, 'MyStack');

在上面的示例中，我们首先创建了一个VPC，然后创建了一个ElasticBeanstalk环境。通过使用CfnEnvironment构造函数创建ElasticBeanstalk环境，我们可以获取到该环境的ARN。

接下来，我们创建了一个ApiGateway并将其与我们刚创建的VPC关联起来。我们使用VpcLink构造函数创建了一个VpcLink，并将其与ApiGateway关联。然后，我们使用AwsIntegration构造函数创建了一个与ElasticBeanstalk环境的集成，并将其与ApiGateway关联。

最后，我们将Integration添加到ApiGateway资源上，以便在POST请求时触发与ElasticBeanstalk环境的交互。

请注意，上面的示例代码是以TypeScript编写的，您需要在项目中安装相应的依赖包。您还需要根据实际情况添加所需的配置和其他资源。