To upload Dolby Atmos audio to DistroKid, you will first need to create and export a Dolby Atmos compatible WAV file.
To get started mixing/creating in Atmos you'll need an Atmos compatible DAW, like Pro Tools Ultimate, Logic Pro, Steinberg Nuendo or Ableton Live. Dolby Atmos Production Suite and something to monitor on. For more information about required plug-ins and compatibility, check out the Dolby FAQ
Once you have everything setup there are tons of great articles and videos you can find to help you get started. Here's one we loved, check it out!
Here are some other articles we found that might be helpful in making your Dolby Atmos content:
Mixing Music In Dolby Atmos - Everything You Need To Know
How To Mix Dolby Atmos For Music - Expert Tutorial
Explore How to Create Music in Dolby Atmos