Concurrency: How to use multiple proxies / session pool IDs?

import { ProxyConfiguration } from 'crawlee';
import { SMART_PROXY_DATACENTER_IPS } from '../utils/proxies.js';

import ApplicationRouter from './ApplicationRouter.js';


export default class TestProxies extends ApplicationRouter {

  async setup() {
    this.version = 1;
    this.prefix = 'TestProxies';
    this.datasetName = `${this.prefix}_dataset_V${this.version}`;
  }

  async getInitialPages() {
    return [
      { url: "https://ifconfig.co/?a=1", label: "page" },
      { url: "https://ifconfig.co/?a=2", label: "page" },
      { url: "https://ifconfig.co/?a=3", label: "page" },
      { url: "https://ifconfig.co/?a=4", label: "page" },
    ];
  }

  getRequestQueueName() {
    return `${this.prefix}_queue`;
  }

  getPageRoot() {
    return 'https://ifconfig.co';
  }

  // This is the entry
  async visitPage() {
    const ip = await this.text({ css: "#output" })
    this.debug("Proxy IP is", ip);

    await this.sleep(4000);
  }

  async getCrawlerOptions() {
    return {
      maxRequestRetries: 3,
      maxConcurrency: 2,

      useSessionPool: true,
      sessionPoolOptions: {
        maxPoolSize: 25,

        sessionOptions: {
          maxUsageCount: 150,
          maxAgeSecs: 23*60, // IPs rotate after 30 minutes
        },

        persistStateKeyValueStoreId: `${this.prefix}_V${this.version}_sessions`,
        persistStateKey: `${this.prefix}_V${this.version}_my-session-pool`,
      },

      proxyConfiguration: new ProxyConfiguration({
        proxyUrls: SMART_PROXY_DATACENTER_IPS
      })
    }
  }

}