By default, if job costing is enabled, then upon pushing Clock IN, the worker will be prompted to select a job from the list of available jobs. Some organizations prefer instead to lock a device to a particular job. For example, this can be useful if a crew is all working on the same job site for the day, and the supervisor can update the locked job each day.
To set that up, go in the Console to Settings => Devices, select the particular job, as follows:
If only Simple costing is enabled, then there will just be an option to select a Job. If Enhancing costing is enabled, then all the costing options will be available to lock. If "Costing Selection is Partial" is enabled, then you can lock down some options and leave the others unlocked for the worker to select. For example, you may just want to lock down the Job, but have the worker select the Job Phase.
The supervisor or administrator can also update these lock settings in the app itself from the Settings option in the left menu. See the "Fixate job" option in the screenshot below.