On the 18th of December Ashes of Creation starts with an Open Beta which everybody can sign up for and play for free!
“Apocalypse” will persist as a standalone "experience" alongside the current development and will include Battle Royale, Siege mode and Horde mode.
If you are interested and have not yet created an account for Ashes of Creation, click this link to sign up: https://apocalypse.ashesofcreation.com/