Issues with headless browser

[HughSparks]

Running - article-epub.py -d 10.1371/journal.pone.0226138

Returns: Getting URL from DOI........done Matched URL to publisher: PLoS ONE Starting headless browser...Message: Unable to obtain driver for firefox; For documentation on this error, please visit: https://www.selenium.dev/documentation/webdriver/troubleshooting/errors/driver_location

I have firefox fully installed as well as geckodriver downloaded and added to my $PATH

I have attempted to create a headless version of firefox with xvfb with no avail. Perhaps I am missing a step however any clarification on "firefox with headless support" would be greatly appreciated.