If you have multiple headsets to manage, you may wish to consider using a device manager to make this task easier. Using this solution, you can install UbiSim as well as push updates on multiple headsets at once. You can read where to find the APK file that is needed when using a device manager here.
While we cannot recommend any particular device management solution, the two most popular ones that we see customers using are Arbor XR and Meta Quest for Business. We encourage you to reach out to them (or any other device management solution not mentioned here) if you wish to learn more about which solution best fits your needs.
Please Note: Even if using a device manager, the headset set up process will still require that you set up each headset individually with its own unique Meta account. If one Meta account is shared across multiple headsets, it will cause access issues with UbiSim and possibly other apps as well.