through trial and error i finally found out where the save on my rom is, it's writen into the rom seperately, here is the address i found out:
1st bank: 000D2000
2nd bank: 000D6000
3rd bank: 000DA000
4rd bank: 000DE000
all 4 bank has length of 2000
so to extract the save have to manual extract the data, paste all 4 part into a new file, then after save it can be read by PKHeX
i tried to insert another old save file i have in by, well, insert 1 part each into their place, then save change to the rom file, use flashgbx to write the modified rom back to the catridge, and it work.
Honestly, i shoudn't have been able to find these, without the help of BennVenn, he create a tool, which can extract the save file out of the rom, which i use it to look back into the rom and find where those 4 bank are stored, and can insert other save into it, without his program, i woudn't have any way to find out those address