PutPut no, you can either subscribe to IW4MAdmin plugins or install them manually by download the plugins files and placing them manually.
I never got subscription to work flawlessly so I gave up on this and thus I cannot help you with subscriptions.
Normally you install a plugin, reboot IW4MAdmin and it asks you to configure the plugin in IW4M's cmd or for some plugins you edit the json files
To give you an example this is what I have because I configured it when re-running IW4MAdmin
b597f9f7-45c0-4ca7-b8f8-3db81295791d-image.png
And here's my plugin installation, as a file
f3bf7dac-d013-402d-af9c-16cf1827341b-image.png