Custome PHP into one specific module

Is it possible to go into the raw code for a particular module and add in some custom php code? IE I created a module Hello1 which goes in a particular page, I want only that Hello1 module to execute PHP code.


If so where are the modules which I created kept in the file manager?

Hi,
you can use Custom PHP/JS module whatever you want. Which is safe.
Sure you can customize any module which you do it your own risk.

I suggest to read also about how to build a module / joomla extension/ in b00k.