Download Qt 5.15.2 Offline: Installer [portable]
Qt 5.15.2 offline installers are no longer provided for open-source users. Starting with Qt 5.15, the Qt Company restricted offline installers and long-term support (LTS) binaries to commercial license holders
Offline installers are preferred by developers for several reasons: download qt 5.15.2 offline installer
Part 7: Legal & Licensing – The Open Source Obligation
The Ultimate Guide to Download the Qt 5.15.2 Offline Installer
for open-source versions starting with Qt 5.15. Your options are: Install Qt creator 5.15.2 - Qt Forum download qt 5.15.2 offline installer