The desktop runs a cron job to sync every X minutes with a taskwarrior server on an amazon instance. The cellphone syncs manually, or you can automate a sync installing Taskwarrior for Android. The UI of this Taskwarrior for Android app is not very good for me, but it allows you to sync the taskdata files every X minutes if you want. You only need to make sure to point the app to the termux .task folder so both the Taskwarrior for Android and the Termux + Taskwarrior CLI use the same data files.