Hi @Rajsahab you may be able to repair as @Pugs1957 has stated. see some of the available tools here https://www.stellarinfo.com/blog/pictures-disappeared-from-sd-card/
However they are older technology and can be prone to some problems though some cards better than others , pros and cons here https://www.hitechwhizz.com/2020/10/7-advantages-and-disadvantages-drawbacks-benefits-of-memory-card...
It is certainly advisable to back up your SD card, particularly if you have precious memories on it.
I do not work for Samsung or make Samsung Products but provide independent advice and valuable contributions.
My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 4.0,Android 12 Official Version.