To create a fee for a customer, click on "Fees" in the menu bar on the customer's page. Click "Add" on the top right. You will then need to select the reservation that the fee you are adding is associated with. Next, input the dollar value of the fee, choose the location, and the reason. You can then add details such as "Damaged Vehicle". The checkbox at the bottom allows you to opt-in to sending an email notification to the customer about the fee.
Invoices typically take about 15 minutes to send. If you would like to send the invoice manually, on the invoice tab, under actions, select the "Trigger Payment" button.