So you have cloned a repo and made some changes to build config, and want to test it without merging it into the main codebase,

you can run your project after changing the build config,

local changes in the code wont get updated in the online code repository, if you are using version control tools like github,

your code repo from which you cloned the project will only get updated if you push your changes to it via git.

I tried running the actual build command on the actual local codebase which prompts a question saying 'is this "project_name" project?'.

and to this,normally prompts wont pop when you are building a next/react project just make sure you are running the build command i.e

npm run build

or

yarn build

in a cmd terminal