The Samsung M21 does have Dolby Atmos support. To enable Dolby Atmos on the Samsung M21, go to the phone's settings, then select Sounds and Vibration, and then toggle on the Dolby Atmos switch. You can also adjust the audio settings to your preference by going to Sound Quality and EQ and adjusting the equalizer and UHQ upscaler. Additionally, you can enable Dolby Atmos for gaming specifically by going to the Gaming settings and toggle on the Dolby Atmos for Gaming switch.
It's worth noting that the Samsung M21 has a feature called Adapt Sound that automatically adjusts the audio settings based on the type of content being played. This feature can be enabled or disabled in the settings. Overall, the Samsung M21 offers a range of audio features that can enhance the listening experience, including Dolby Atmos.