Dynamical api data when registering module

Good day

Question 1:
I am creating my first own module for BeaverBuilder with help of the official guide. The goal is to display and style calendar appointments from an API.
When I register my modul (FLBuilder::register_module) id like to enclose which calendar categories are displayed. To achive that, I’d like to have a select field, which displays the selectable categories.
To get the categories from the API I need the source link, which is from another settings field.
As I can only get these categories after I register the module, I can’t put them as options in my select field.
Any ideas?

Question 2:
To use less date, we cache all the api data, with an interval how long there should not be a new api request.
As some settings of the module have influence on the api, I’d like a way to verify if a specific setting has changed.

Thank you for your help.