How to set a fixed price for a task?

The final task price is calculated based on either time spent and additional costs (materials, travel expenses) or based on the pre-agreed price, that you and the client set.
When based on an hourly rate, the timer must be set once the task has started and terminated once the task is completed. When the parties have agreed upon a fixed price, the Tasker must set the timer and then insert the fixed price next to the timer field named “Fixed price” and end the task.