How to get logs in a V4 printer driver under windows 10

Dear Developers,

I need to implement a virtual printer driver under Windows 10 by using V4 printer driver sample.
I can easily compile and install the driver in Windows 10 but I have to enable testing mode on.
But the problem is that I could not get any log from the driver.
I even do not know how to get log from it.
for development purposes, I am in deep need to get logs.
Please help me how to trigger the driver to give me some logs.

Thanks