The service is installed on every sip:carrier system, but is not activated by default. In order to activate the service, connect with SSH to your server, open /etc/ngcp-config/config.yml with your editor of choice and change the fileshare.enable property from no to yes:

fileshare:
  enable: yes

Apply the new configuration in the usual way:

ngcpcfg apply 'Enabled comx-fileshare-service'
ngcpcfg push all

and check the status with monit summary. It should be now up and running.