Once you've set your Umbrella Settings you can now see the magic at work.
Start a pay run as usual.
You now just fill in the form.
The "Miles to claim" only appears if you've assigned a vehicle to the employee.
You'll see that the payslip has now been updated. The appropriate amount has been paid at minimum wage, a payment for holiday has been added and the remainder as a Discretionary Profit Sharing Bonus.
If the employee has a pension then the contributions to that have also been taken in to account.
The take-home pay for the employee will be equal to the invoice value you entered, less any costs of employment (employers NI, employer pensions contributions, etc) and whatever fee you set to process the payment for them.