Do you have more than one item to request payment for, or do you want to break down the cost for your customer?
This is simple to do and once you create line items in the payment request, this is automatically created in the invoice.
Create a new payment request > add £ amount
Click on 'Add description' and type the item which refers to this amount > click 'Add item'
Simply repeat the process to add another line item.
As usual you are able to send this request by SMS and/or email. If you have enabled invoices, the payment request will be emailed to your customer along with the itemised invoice.