Headless solution: Cannot add categories

[maujbs]

Hi. I'm not sure what steps I'm missing:

1. I tried to follow the steps and install the packages according to the README file.
2. I have no access to the DbContext (since it is headless)
3. I read that I need to add a new table to my DB, but using SqlClient is not an option. Can you provide which steps are required to add a Geta Category to my solution?
4. By now, I added fields using BasicCategory and ExtendedCategory, as well as using the [Category] from Geta. This shows me a dialog with no categories. (Since I still cannot add anything).

Thanks for your help