HBO Max provides Dolby Atmos apart from utilizing a streaming device that supports 4K content. Below are requirements that need to be fulfilled to watch HBO Max in 4K with Dolby Atmos audio:
High-speed internet connection
4K HDR TV with Dolby Vision or HDR10
A sound system, or headphones, that supports Dolby Atmos
HBO Max must automatically play your chosen movie in 4K HDR relying on your connection speed and network capacity if your devices match the above-mentioned criteria and the movie you wish to see is available in 4K.