You do not need admin rights to install the plugin on Windows.
Installing with admin rights is supported, but not needed. It comes two limitations :
- even with admin rights, the plugin is only installed per user,
- if you installed the plugin as admin, you can only "repair" it as admin (when relaunching the installer)
Updates are removal can be done with or without admin rights.
You do need admin rights to install the plugin on macOS.
Once the plugin is installed, you can run it without admin rights.