When trying to add the Rundeck CLI Debian repository to the list of sources, I get:
Failed to update apt cache: E:The repository 'https://packagecloud.io/pagerduty/rundeck/ubuntu focal Release' does not have a Release file.
The URL https://packagecloud.io/pagerduty/rundeck/ubuntu/ results in a 404:
The page you were looking for doesn't exist.
You may have mistyped the address or the page may have moved.
If you are the application owner check the logs for more information.
So neither the script nor the instructions at https://packagecloud.io/pagerduty/rundeck/install#manual-deb are working. It appears as though debs can only be installed manually.
FWIW, https://packagecloud.io/pagerduty/rundeck/any/ doesn't work either.