I am trying to develop an environment based on the prx ESB sample and add nrfx_timer.h dependencies. This is not necessarily a question specific to this setup but a more general question. I see the documentation points out a sdk_config.h file but I do not see that anywhere. My samples do that contain that file. But there is a .config file that can be configured witha GUI. However the changes I make never seem to get saved. I used nRF Connect and Toolchain Manager to setup the environment for VS Code. The .config is contained here: C:\nordic\myapps\prx\build\zephyr and my SDK directory does not contain examples. But the examples do work, Please let me know where i went wrong.