i got this error from instaling cpanel/whm

i'm just beginer and still don't know much, i just follow this youtube (1QaFYXbWDaw) video to instal cpanel and whm for my thing* and i got this problem please help me Verifying archive integrity... All good. Uncompressing cPanel & WHM Installer...... ____ _ ___| _ \ __ _ _ __ ___| | / __| |_) / _` | '_ \ / _ \ | | (__| __/ (_| | | | | __/ | \___|_| \__,_|_| |_|\___|_| Installer Version v00097 rfc9e3cc20b51698d65f242183461de59649b63a8 Beginning main installation. 2020-03-21 22:24:02 929 [3517] ( INFO): cPanel & WHM installation started at: Sat Mar 21 22:24:02 2020! 2020-03-21 22:24:02 930 [3517] ( INFO): This installation will require 10-50 minutes, depending on your hardware and network. 2020-03-21 22:24:02 931 [3517] ( INFO): Now is the time to go get another cup of coffee/jolt. 2020-03-21 22:24:02 932 [3517] ( INFO): The install will log to the /var/log/cpanel-install.log file. 2020-03-21 22:24:02 933 [3517] ( INFO): 2020-03-21 22:24:02 934 [3517] ( INFO): Beginning Installation v3... 2020-03-21 22:24:03 579 [3517] (DEBUG): Detected distro "centos-release", version "7.7", arch "x86_64" 2020-03-21 22:24:03 603 [3517] ( INFO): CentOS 7.7 (Linux) detected! 2020-03-21 22:24:03 618 [3517] ( INFO): Checking RAM now... 2020-03-21 22:24:03 678 [3517] ( INFO): Validating that the system hostname ('domain-example.com') is a FQDN... 2020-03-21 22:24:03 684 [3517] (ERROR): 2020-03-21 22:24:03 685 [3517] (ERROR): ********************* ERROR ********************* 2020-03-21 22:24:03 686 [3517] (ERROR): 2020-03-21 22:24:03 687 [3517] (ERROR): Your hostname (domain-example.com) is invalid, and must be 2020-03-21 22:24:03 688 [3517] (ERROR): set to a fully qualified domain name before installing cPanel. 2020-03-21 22:24:03 689 [3517] (ERROR): 2020-03-21 22:24:03 690 [3517] (ERROR): A fully qualified domain name must contain two dots, and consists of two parts: the hostname and the domain name. 2020-03-21 22:24:03 691 [3517] (ERROR): You can update your hostname by running `hostname your-hostname.example.com`, then re-running the installer. 2020-03-21 22:24:03 693 [3517] (ERROR): ********************* ERROR ********************* 2020-03-21 22:24:03 694 [3517] (FATAL): Exiting... Removing /root/installer.lock.