How to maximize the browser screen？

1.Manually add custom parameters to a single configuration file:
Edit the browser configuration file -> Other Configuration -> Customize startup browser parameters -> Fill in "--start-maximized" -> Save.

2.Automatically add custom parameters to newly created configuration files.
System Settings -> Preferences -> Customize startup browser parameters -> Fill in "--start-maximized" -> Save settings.
This browser parameter will be automatically added to the newly created configuration files. For old browser configuration files, need to set this parameter manually according to the first way--Add this parameter in a single configuration file.