Due to the age of PyQt4 it is not available anymore on Ubuntu 20.4.
Additionally it is not officially supported anymore and doesn't get new releases anymore according to the official page: https://riverbankcomputing.com/software/pyqt/intro
As far as I see the Module was used for the QString option. This class is not available in Python3 anymore, because Python 3 is automatically Unicode compatible. So for all Python 3 running devices, the plugin is broken.
A workaround is found here:
http://inputvalidation.blogspot.com/2010/10/python3-pyqt4-and-missing-qstring.html
But it seems to provide some issues as well.
I also found another line, where the code is Python3 incompatible, because it uses dict.iteritems(), this can easily be fixed doing dict.items() instead.
Due to the age of PyQt4 it is not available anymore on Ubuntu 20.4. Additionally it is not officially supported anymore and doesn't get new releases anymore according to the official page: https://riverbankcomputing.com/software/pyqt/intro As far as I see the Module was used for the QString option. This class is not available in Python3 anymore, because Python 3 is automatically Unicode compatible. So for all Python 3 running devices, the plugin is broken. A workaround is found here: http://inputvalidation.blogspot.com/2010/10/python3-pyqt4-and-missing-qstring.html But it seems to provide some issues as well.
I also found another line, where the code is Python3 incompatible, because it uses dict.iteritems(), this can easily be fixed doing dict.items() instead.