How to use this plugin?

[SlySven]

I'm trying to make a switch from linuxdeployqt to linuxdeploy making use of the linuxdeploy-plugin-qt- and one uses THAT plugin by getting its AppImage and placing it alongside the main linuxdeploy one. However I also think I will need this one to get gstreamerlibraries into the project I am working on but there is no published AppImage for this project - admittedly it does seem to be a single shell script - but how do I source and get that script to be used by the linuxdeploy.AppImage?