Hi @micware, you’re not doing anything wrong. This is a bug with our repository which we are currently waiting on a fix. This issue comes and goes and I haven’t figured out a pattern to when it starts or stops yet.
Did you come from: Guide: Installing and testing OH3 snapshots using APT and YUM ?
If so, there’s a section in that same post for a workaround on the issue you’re experiencing:
wget https://openhab.jfrog.io/openhab/list/openhab-linuxpkg/pool/main/3.0.0~S1926/openhab_3.0.0~S1926-1_all.deb
sudo apt install ./openhab_3.0.0~S1926-1_all.deb
where S1926 should be the latest build inside this folder. (1926 is the latest at the time of writing this post).