There are appealing theoretical reasons to think an axion exists [strong-cp]; there are appealing theoretical reasons to think an axion does not exist [chiral]. What this device can do is explore. They may come up empty because dark matter is not axions; they may come up empty because dark matter is axions but the physical parameters are surprising. But people agree that
if axions comprise any sizeable fraction of dark matter then its parameters should be between
this and
that, and this device can find it there.
[strong-cp] https://en.wikipedia.org/wiki/Strong_CP_problem
[chiral] https://arxiv.org/abs/2412.02024