Download the latest qt-online-installer for your OS.

This is the standard way to get 5.15.2. You must log in with a Qt Account to use it. : Get the Online Installer from the official site. Locate 5.15.2 : Launch the installer and log in. Select Custom installation .

Download the Source Packages from the public archive and compile them yourself. ⚠️ Important Considerations Install Qt creator 5.15.2 - Qt Forum

Because 5.15.2 is open-source, no license key is required during installation. Simply click "Next" through the wizard.

for open-source users. These installers are now exclusively available to commercial license holders through the Qt Account portal