Installation Error - Unable to locate package virtualmin-core

My installation page---

▣□□ Phase 1 of 3: Setup Downloading RPM-GPG-KEY-virtualmin-6 [ ✔ ] Downloading RPM-GPG-KEY-webmin [ ✔ ] Installing Virtualmin 6 key [ ✔ ] Installing Webmin key [ ✔ ] Updating apt metadata [ ✔ ] Downloading repository metadata [ ✔ ] Enabling universe repositories, if not already available [ ✔ ] Disabling cdrom: repositories [ ✔ ] Cleaning out old metadata [ ✔ ]

▣▣□ Phase 2 of 3: Installation Installing Webmin [ ✔ ] Installing Usermin [ ✔ ] Installing fail2ban [ ✔ ] Removing nginx (if installed) before LAMP installation. [ ✔ ] Removing unneeded packages that could confict with LAMP stack. [ ✔ ] Installing postfix [ ✔ ] Installing virtualmin-lamp-stack [ ✔ ] Installing Virtualmin and plugins [ERROR] Failed with error: 100 [ ✘ ]

[ERROR] Something went wrong. Exiting. [ERROR] The last few log entries were: Processing triggers for ureadahead (0.100.0-21) ... Processing triggers for libc-bin (2.27-3ubuntu1) ... Processing triggers for systemd (237-3ubuntu10.39) ... Processing triggers for man-db (2.8.3-2ubuntu0.1) ... Processing triggers for dbus (1.12.2-1ubuntu1.1) ... Processing triggers for ufw (0.36-0ubuntu0.18.04.1) ... Installing virtualmin-lamp-stack: Success. Spin pid is: 4121 Reading package lists... Building dependency tree... Reading state information... E: Unable to locate package virtualmin-core Installing Virtualmin and plugins: [2020-04-23 15:11:38 UTC] [ERROR] Failed with error: 100 [2020-04-23 15:11:38 UTC] [ERROR] Something went wrong. Exiting.