Writing bluetooth LE app

I want to write an app for my extraction hood (Airodesign Estrella).

It has a remote that communicates with the extraction hood using Bluetooth LE. I have opened the remote and it has a “u-blox nina B112” bluetooth module.

I have done a little research and found this, but I’m not sure how to start.

Could anyone help me get started?

Do you already have a basic app running? Have you looked here? Did you check out the example app on aforementioned page?