I want recovery my storage size

My phone is Galaxy Wide4 (SM-A205S Korean SKT model).

I successfully installed a custom kernel today with the help of the xda forum, but I was amazed that the built-in storage was only 6GB. (Stock: 32GB)
I tryed find my partion table in TWRP…… but I don’t known this problem.

Maybe I formatted the data partition once in TWRP that.

It seems that I used gdisk and fdisk to do similar actions while searching on Google, but my Android doesn’t seem to work as the data partition is automatically encrypted in TWRP and is not recognized.

Custom kernel: Eureka SM-A20xx

I want this problem solution. Thanks.