qgis-webappbuilder-plugin-master.zip INSTALLATION

[naiyar5j]

I am getting the following error while trying to install qgis-webappbuilder-plugin-master.zip:
"An error occurred during execution of following code:
pyplugin_installer.instance().installFromZipFile(r'C:\Users\Naiyar\Downloads\qgis-webappbuilder-plugin-master.zip')

traceback.print_exception() failed

Python version:

QGIS version:
3.4.4-Madeira 'Madeira', f6ddc62fdb

Python path:
"
Kindly help to resolve it.
Thanks in advance
naiyar5j