CodeIgniter project download from GitHub

I've cloned a project from GitHub, developed with CodeIgniter using Composer, which I want to extend.

To get this working on my own PC do I need to follow the instructions Adding CodeIgniter4 to an Existing Project? This talks about copying files and folders like app, public, tests etc from vendor/codeigniter4/framework to the project root. However there are files and folders of these names already in the project root downloaded from GitHub.

I’ve completed the CodeIgniter first app tutorial if that makes any difference.

Grateful for any help or advice. Thanks.