How to install plugins in kimai docker

i’ve recently installed the Kimai docker image (GitHub - linuxserver/docker-kimai) and everything is working as expected, however I dont see a way to install plugins. I have mapped the config directory to the host machine, which is working correctly.
For example the Easy Backup Plugin would be installed into var/plugins/EasyBackupBundle/, which doesnt seem to exist in the docker image.
Is there another way to install plugins in the Kimai image?