customization – Custom Woo-Commerce Product Options

I’ve been provided with a test task to implement custom woo-commerce product options functionality just as it is implemented in this screenshot

enter image description here

Task:
The task is to include toppings from the “add something extra” section into the “change toppings, sauce or cheese” section.

Conditions are:

  1. can not add more than 5 extra toppings
  2. no price will be charged for a maximum of 4 toppings
  3. all toppings will be charged as defined prices if more than 4
  4. price of toppings must add up in the total (add to my basket button).

My questions:

  1. I’ve not been provided with any backend login credentials. Can I do this using javascript in some browser development tools?
  2. Any ideas to implement such functionality?

Thank you.