Packages for RHEL 7 and SLES 12 are built without HTTP/3 support because OpenSSL used by those doesn't support TLSv1.3. Before you install nginx for the first time on a new machine, you need to set up the nginx packages repository. Afterward, you can install and update nginx from the repository. This section applies to Red Hat Enterprise Linux and its derivatives such as CentOS, Oracle Linux, Rock