Open Chrome browser
Open Chrome menu by clicking on 3 dots on top right then "More tools"
On the contextual window, click on "developpement tools"
The development console will then open, go to "Console" located at the top, then right click on one of the logs to make a "Save as", save them in .log format in a chosen folder.
The menu will then appear from the top, just check the box "Preserve logs".