On Get on Board, all published jobs (except those in part-time and freelance modes) must specify salary.
The salary offered can be hidden from public view(*), this option is available for subscription plans when you create a job on Get On Board. Applicants to your job will always be able to view the salary range you indicate privately.
If you need help calculating the salary range you can find it here.
(*) Please note that professionals will be able to see the maximum salary range if they enter an amount higher than this at the time of filing their application.