I'm quite new to digital signatures and I'm trying to make my .NET application appear as secure when people run it on different computers. I have generated myself a Let's Encrypt certificate and it works as expected on my web page. Following various resources I converted the certificate to PFX and tried to use it for digital signing, but then VS yells that "The selected certificate file is not valid for code signing". When I ran SignTool on my EXE file, I got an error "No certificates were found that met all the given criteria" and debugging showed that my cert didn't pass the EKU filter.
Is what I'm trying to achieve even possible? And if so, what am I doing wrong?