So you say you aren’t looking for mapping,
but remember that when you say “localize” you had have to localize yourself w.r.t something, a reference. I would guess what you mean is, you just want an odometry estimation, meaning that you want to recieve your localization information w.r.t your initial pose ? Is this what you mean ?
If so, you are not limited to use laser scanner/lidar based slam methods. You can also use a camera based visual slam method such as RTABMap, OpenVSLAM or ORB-SLAM. I have used AMCL but haven’t used the other one, and as far as I remember you had need to provide a prebuilt map, and guessed initial pose to AMCL to start localization. In addition to both those methods there is google cartographer slam package,