Observe: Produce a file underneath /etc/apt/resources.list.d, not the /etc/apt/sources.checklist file wherever the distribution's official repository addresses are located. This is the approach that will not destabilize your procedure. It is suggested. So as to grant certificates to shopper origins, CloudFlare experienced to create its own Certificate Authority. This is https://www.hostscheap.com/magento-2-install-service