问如何在redbird代理服务器上续订ssl证书

EN

const proxy = require('redbird')({
  port: 80,
  xfwd: false,
  letsencrypt: {
    path: "certs",
    port: 4444
  },
  ssl: {
    port: 443
  }
});

proxy.register("domain.com", "http://localhost:3000", {
    ssl: {
      letsencrypt: {
        email: "email@gmail.com",
        production: true
      }
    }
});

proxy.register("www.domain.com", "http://localhost:3000", {
    ssl: {
      letsencrypt: {
        email: "email.com",
        production: true
      }
    }
});

drwxr-xr-x   8 root    root     4096 Mar 27 22:23 certs 
drwxrwxr-x 157 redbird redbird  4096 Mar 27 21:33 node_modules
-rw-rw-r--   1 redbird redbird   142 Mar 27 21:33 package.json
-rw-rw-r--   1 redbird redbird   887 Aug 23 22:40 server.js
-rw-rw-r--   1 redbird redbird 48105 Mar 27 21:33 yarn.lock