How do I call api and load json data into array?

How do I call api and load json data into array?

for example

I want to call api from (https://api.covid19api.com/summary)

I used (https://www.youtube.com/watch?v=hw6U35J5EN0) this video to call api but in this example How do I load "countries" data into array?

You need to request this url with AJAX and parse it to JSON object. Then, if you want, you can copy data from JSON into an array.

There is a template in C3 showing how to read from JSON.