Hello Wedding, Jan,
Welcome to the MS Q&A Forum.
Unfortunately Dependency Agent is currently not available on Ubuntu 22.04, due to product design. I attempted to obtain information on the ETA internally, but the only explanation we received is that there are no short term plans for adding supportability on Ubuntu 22.04.
I found the similar feature request "Make OmsAgentForLinux and DependencyAgentLinux extensions available for Ubuntu 22.04 LTS" already raised in on the feedback forum. If interested, you may upvote it. In general, Azure feature or product team would check feasibility of a feature request, prioritize against existing feature backlog, add them in roadmap as appropriate and would announce and/or update the related Azure document once a feature request is addressed.
Hope above answers your question.
Sincerely,
Olga Os.