The G203 has onboard memory (which also includes RGB light state / startup effect and DPI steps), so once you have your settings right you can just store the profile in the mouse and uninstall the software.

The latest version of the Logitech software (G HUB) doesn't make this feature obvious though, you have to set a local profile then click the gear icon > my gear > click the mouse image > switch on on-board memory mode > click Slot 1 (Default) > click replace with [the profile you just customized, usually Desktop (default.)

The old Logitech Gaming Software was much simpler in this regard.