The standard installer for Qt 5.15.3 is typically obtained through the Qt Online Installer. While "qt-opensource-linux-x64-5.15.3.run" often refers to an offline binary, the Qt Company has moved away from providing standalone offline installers for open-source users for versions 5.15 and later. How to Download and Install Qt 5.15.3 on Linux
Expand the tab, then Qt 5.15.3 , and select the desktop components for your architecture (gcc 64-bit). Why the 5.15.3 .run File is Unique qt-opensource-linux-x64-5.15.3.run download
: Visit the Qt Open Source Download page and download the qt-unified-linux-x64-online.run file. Make it Executable : Open your terminal and run: chmod +x qt-unified-linux-x64-online.run Use code with caution. The standard installer for Qt 5