How to traverse array in json?

Question

https://code.sololearn.com/WbcS9F9AV6K7/?ref=app

I want to take what was passed in the URL as a parameter, and compare, to see if it has json in category

The problem is that, as it is, it works, but only if it has 1 value in category, if it has two or more, it no longer prints anything on the screen.

See the code, and please help me :(

Answer 1

https://code.sololearn.com/WX2CwmYR8lIo/?ref=app
https://code.sololearn.com/WbfJmVR5cCsA/?ref=app

Answer 2

I don't understand much this :( I'm noob