Unfortunately, my attempts to get Aternos to permit the use of the Herobrine plugin on their platform have failed. This means that users of their service will not be able to use this plugin. Since their approach to handling this request suggests that they are unwilling to accommodate their customers, my recommendation for server admins who want to use Herobrine is to use an alternative hosting solution. My recommendation would be to migrate to
Apex Hosting. Unlike Aternos, Apex allows you to upload and use whatever plugins you would like to for your server. I use them as my hosting provider and have absolutely no complaints about the quality of their service.