Why doesn't the data on the site page change when the repository is built?

Question

Node.js

Good day! I downloaded the site from the git repository. I install Node js in the folder with the repository. I change the code. I build the project. And I run it on the local server. But the changes I made do not appear. I tried clearing the cache. Copy to another folder and delete the old one. Nothing does not help. What could be the reason for this? And how can I make the changes I made to the code appear?
Here I found something but these tips do not help
https://coderoad.ru/54024181/npm-%D0%B7%D0%B0%D0%B...