Redirect the console log output to a file

We are working with Firefox Portable ESR 78.6.0 on windows 10 OS
We want to write logs in a txt file. To do this, we used window.dump ("txt") in js files.
we have set the configurations from about:config :
"browser.dom.window.dump.enabled" to true and "browser.dom.window.dump.file" : "c:\file.txt". (we tried other locations)
the result is always : the file is created but it is still empty.
Is there another configuration to do or another way to redirect the console log output to a file?

Thank you.