Qt install offline

The installer is only asking for login credentials when it can reach the internet, so if you don't have network access, you will have the skip button.

If you want to deploy it without logging in—even when the PC is connected to the internet—you have to temporarily delete the default route (0.0.0.0). That way the installer cannot contact the server and will provide you with the skip button.

According to this page, you should have a "skip" button if you clear all Qt account fields.