Important Note: Qt 5.15.2 was released in 2020. For open-source users, offline installers for versions after 5.15.2 require a commercial license. Qt 5.15.2 is the last version with easily accessible official offline installers for open-source use.
Look for the correct installer file based on your OS: download qt 5.15.2 offline installer
Example: aqt install-qt windows desktop 5.15.2 win64_msvc2019_64 Important Note: Qt 5
Why Use an Offline Installer?