Thank you for your response.
1.
The .json shows lower amount of the target files.
E.g. the target were “10”, but the .json file’s “posts_count” is “2”.
2.
When I import, the .json file’s amount is imported.
BTW, I guess this might be because of my server RAM configuration issue.
So, I’m just making the target amount as 1 ~ 2 for exporting.
Anyway, thank you so much for your kind answer…!