There is no way to do this for free.  If you want to sign your executables, you will need to buy a code-signing certificate and use signtool to sign them.  Code signing certificates cost about $300 per year.  signtool is part of the Windows SDK; you can get it in the free "community" editions of Visual Studio.
I work on one project in that code in python script.py and with help of pyinstaller build exe file but issue is that I want to add publisher name in exe file. FREE
exe with publisher name
I browse on google but I do not get a solution.

i don't have a code sign certificate.
I don't have a signtool
i don't know how to connect a self sign certificate with an exe file.

Please guide me.
how to add Publisher Name in Pyinstaller exe file