Change in the Source Code of Frappe- Bench

Hello,
I am new to Frappe. I am tried to change the source code but there was no change reflected . How can i make the changes directly from source code . I am using it as a test purpose in my own local machine.
Please, i need your help. Thanks in advance.

Regards,
Biozid Bostami

@biozid welcome to the forum!

This is a good place to start: Not Found