This will open a new window which is linked to the PayPal payment system. You will see an invoice for a single item, Additional Charge (eg. Delivery), for which the amount is blank.
step 1 Just fill in the amount of the payment you need to make to Monarch.
step 2 Then either add your PayPal account details and click 'Continue' or if you don't have a PayPal account click the link for this eventuality which will allow you to pay by credit card.