How to use the pouchdb-adapter-idb.default function in pouchdb-adapter-idb

import PouchDB from 'pouchdb-core'

// All Environments
let configuredPouch = PouchDB
  .plugin(require('pouchdb-find').default)

if(process.env["NODE_ENV"] === 'test' && typeof window === 'undefined') {
  // Node tests, include extra libs for speed
  configuredPouch
    .plugin(require('pouchdb-adapter-memory').default)
  configuredPouch = configuredPouch.defaults({ adapter: 'memory' })
} else {
  // Any environment with a window
  configuredPouch
    .plugin(require('pouchdb-adapter-idb').default)
    .plugin(require('pouchdb-adapter-websql').default)
}

export default configuredPouch

.plugin(require('pouchdb-replication'))
    .plugin(require('pouchdb-mapreduce'))
    .plugin(require('pouchdb-find'))
    .plugin(require('pouchdb-adapter-memory'));
}
else {
  if(window.PouchDB) {
    PouchDB = window.PouchDB;
  }
  else {
    PouchDB = window.PouchDB = require('pouchdb-core').default
      .plugin(require('pouchdb-adapter-http').default)
      .plugin(require('pouchdb-replication').default)
      .plugin(require('pouchdb-mapreduce').default)
      .plugin(require('pouchdb-find').default)
      .plugin(require('pouchdb-adapter-idb').default);
  }
}
var PouchDB$1 = PouchDB;

function adapter({AbstracrAdapter}) {
  const fieldsToDelete = '_id,search,timestamp'.split(',');
  return class AdapterPouch extends AbstracrAdapter {
    constructor($p) {
      super($p);
      this.props = {
        _data_loaded: false,
        _doc_ram_loading: false,
        _doc_ram_loaded: false,
        _auth: null,
        _suffix: '',
        _user: '',

.plugin(require('pouchdb-mapreduce'))
    .plugin(require('pouchdb-find'))
    .plugin(require('pouchdb-adapter-memory'));
}
else {
  if(window.PouchDB) {
    PouchDB = window.PouchDB;
  }
  else {
    //const ua = (typeof navigator !== 'undefined' && navigator.userAgent) ? navigator.userAgent.toLowerCase() : '';
    PouchDB = window.PouchDB = require('pouchdb-core').default
      .plugin(require('pouchdb-adapter-http').default)
      .plugin(require('pouchdb-replication').default)
      .plugin(require('pouchdb-mapreduce').default)
      .plugin(require('pouchdb-find').default)
      .plugin(require('pouchdb-adapter-idb').default);
  }
}

export default PouchDB;