You have two ways to keep the Certification Authorities file up-to-date:
This package installs the Update HTTPS Client Certificate job.
You can run it manually in your dashboard (under System & Settings → Optimization → Automated Jobs), or you can schedule it (more details here).
You can execute the hcc:update-https-client-certificate CLI command. In order to get the list of available options, you can run:
concrete/bin/concrete5 help hcc:update-https-client-certificate
(If you are not familiar with concrete5 console commands you can read this page).