PageSpeed Insights -> Eliminating resources blocking rendering?

Dear Support-Team, PageSpeed Insights results lists among others the following resources that block the site's first paint and tells me to put important JS and CSS inline and defer all non-critical JS and styles: genericons/genericons.css?ver=3.4.1 (www.stiftung-meeresschutz.org) …jquery/jquery.min.js?ver=3.5.1 (www.stiftung-meeresschutz.org) Is this anything you can help with like adding that to the additional CSS in the customizer? Would be great to hear your ideas on that. Thanks and best regards Ulrich at: https://www.stiftung-meeresschutz.org/