Modify your ‘/etc/apt/sources.list’ file to include the -proposed repository as described in how to enable -proposed.
deb http://archive.ubuntu.com/ubuntu/ xenial-proposed main restricted universe
You don’t need to follow the entire list of instructions at how to enable -proposed. Just the step to add the -proposed repo.
Obviously, your repo will be questing-proposed instead of xenial-proposed
Of course, the deb sources and format changed in Ubuntu 25.04, so you won’t be editing sources.list, but instead adding a new file in /etc/apt.sources.list.d/
You don’t need to upload a hardware profile.
It may be even simpler if you are using Ubuntu Desktop. Just check the box (on a Questing system, of course)…
You should make sure to not keep it enabled after you installed your desired package that you want to help testing, so you do not accidentally get other packages installed…
Keep in mind that proposed is used for testing so things can be broken…
No need to disable the proposed source. 25.10 comes with apt 3.1.6 and enabled solver 3.0. You can usee the new options include/exclude to just get the desired package from the source.
