Firstly, you need to confirm the 3D hologram fan version you have, because there are several different versions, is it wifi&SD card version or just wifi version, or wifi & cloud version etc.
LL-HA-50-WF-DS-X &LL-HA-50H-WFC-DS-X LL-HA-65-WF-DS-X & LL-HA-65X-WFC-DS-X & LL-HA-100-WFC-DS-X please download the app from https://www.dseelab.com/resource/software
Remark : Not fit for LL-HA-43-SDWF-FT-X & LL-HA-65X-SWF-ZB-X & LL-HA-100-SWF-ZB-X.
42cm is the SD card version. It is downloading the required material directly to the SD card and then use the controller to control the playback.