https://download.qt.io/archive/qt/5.15/5.15.2/single/ Look for qt-everywhere-src-5.15.2.tar.xz .
https://download.qt.io/archive/qt/5.15/5.15.2/qt-opensource-mac-x64-5.15.2.dmg qt5.15 download
sudo apt install qt5-default qtbase5-dev qtbase5-dev-tools https://download