ahh you installed something like this:
https://packages.icinga.com/centos/8Client/testing/x86_64/icingadb/
and since centos dropped support for centos8 icinga stopped providing packages as well.
well…
your options are the following:
- get a icinga subscription and use centos/alma/rocky Icinga » Subscriptions
- use a “subscription free os” like suse/ubuntu/debian for your master node
- use centos7 but if that runs eol icinga will most likely drop free packages as well.
- compile the packages yourself.