If your team relies on offline installers for compliance or speed, consider a commercial Qt license or start building your own offline repositories using the Maintenance Tool (as shown in Part 5). Do not depend on public open-source offline packages for critical long-term projects.
This is mandatory. If you don't have an account, create one at qt.io. The installer will ping the Qt server to verify your credentials, but it will not download new packages beyond what is already in the offline bundle. Qt6 Offline Installer
Example qt-install-script.qs :