I've looked everywhere and can't seem to find an answer so posting here.
Using a 64bit Lubuntu VM,
Downloaded the Qt online installer from: https://www.qt.io/download-open-source
The correct architecture installer downloaded
After sudo chmod +x "qt-opensource-linux-x64....run"
and typing in ./qt-opensource....
I get:
cannot execute binary file: Exec format error
So I don't really know where to take it from here, I didn't check the checksum because I couldn't find the checksum on Qt's download page but I download it twice in case the download was corrupted and got the same problem on both occasions.