First of all, I wanna thank all of you guys for all your comments. I had gone store to fix it with Apple Configurator 2. It solved directly. I asked if I want to recovery, how may I do? They said; You will have to do;
1)Show all under of SSD ( Normally, you don't see.)
2) Create ex-FAT or another format type.
3)When your mac creates step 2. Then erase it after created. Now, You can create APFS one.
4)Create APFS and issue done.
5)If you want to, use Apple configurator 2 or after step 4 you can install macOS Big Sur again directly.
( if you don't do this, it probably doesn't show you SSD, like there is no SSD .)
That's it. I hope nobody will encounter such a problem.
Have a good day...