I inserted the SD card but it is not being recognized. (YI 4K+ Action Camera)

a. Only SD cards between 16-64GB in size are compatible.

b. Make sure the SD card is in the correct format.

c. The SD card should be in FAT32 format. If it is in Block32KB format, we recommend you enter "Settings -> SD Card -> Format SD Card" on the app or camera LCD screen to format the SD card.