Drupal 8: allow users to filter custom entities on the json api

mymodule.module.php

<?php
// Related to SA-CONTRIB-2018-081
// https://www.drupal.org/node/3036792

function mymodule_jsonapi_asset_filter_access(\Drupal\Core\Entity\EntityTypeInterface $entity_type, \Drupal\Core\Session\AccountInterface $account) {
  return ([
    JSONAPI_FILTER_AMONG_ALL => AccessResult::allowedIfHasPermission($account, 'administer asset entities'),
    JSONAPI_FILTER_AMONG_PUBLISHED => AccessResult::allowedIfHasPermission($account, 'view published asset entities'),
    JSONAPI_FILTER_AMONG_OWN => AccessResult::allowedIfHasPermissions($account, ['view published asset entities', 'view published asset entities'], 'AND'),
  ]);
}

function mymodule_jsonapi_asset_field_filter_access(\Drupal\Core\Field\FieldDefinitionInterface $field_definition, \Drupal\Core\Session\AccountInterface $account) {
  return AccessResult::neutral();
}