I need to find some solution in which i can apply Dependency injection in my Github repo for console application

The below is my Github repo and i am looking to apply dependcy injection in my solution.

https://github.com/aagamdoshi/WeatherAPI-PrudUK

I am not sure from where to start dependency injection or which functionality to pic . The aim of the code is to read data from file and call the Weather Api can store the data in other file

I expect after dependency injection , the code should easily unit testable or moqed