Custom form in admin to add data

Environment: Self-hosting with latest nginx and ghost.

I need to insert specific data like dollar sums and descriptions etc so I can query them in page. Is it possible to my develop page in admin section to do that? I noticed that I can insert JavaScript in blog post so I can show charts and that’s very, very great. Thanks for that.

I like to do insertions in Ghost admin (in one place) or do I have to develop just side app for doing that and then import data to Ghost?