Plase add more function

I want to give more option:
– Subscribe only a particular category, for example selected from the list and even better if it were automatically take into account entries for this category
– Notice not only of content but also when the entry was updated

My problems:
1. https://ps.w.org/subscribe-to-category/assets/screenshot-1.png
Dont have that config page

2. I add [stc-subscribe] in widget, but I have 30 category so list is so long. Coud autotaticly select from category name (as I sad in 1st sentence)

3. https://ps.w.org/subscribe-to-category/assets/screenshot-4.png
Cant have that option on page or other custom page created in my theme

https://wordpress.org/plugins/subscribe-to-category/