Make sure the SD card is properly inserted into the camera. Check if the SD card slot is correctly aligned and ensure there is no resistance when inserting it.
Check if the SD card is damaged. You can try inserting the SD card into another device (such as a computer or another camera) to see if it can be recognized correctly.
If other devices also cannot recognize the SD card, it might be an issue with the SD card itself.
You may consider replacing it with a new one. The capacity of the SD card should be between 32GB and 256GB.