A common question arises in my mind that such a detail sales order invoiced exists then why we need free text invoice. I found two detail answers with reference
A free text invoice is an invoice that is not attached to a sales order. A free text invoice contains a header and one or more lines for items or services that are not tracked in inventory. Use a free text invoice for sales that do not require a sales order, packing slip, and customer invoice. For example, you can use a free text invoice for a consulting fee or services fee, or for a miscellaneous fee for an event reimbursement.
A free text invoice is not related to a sales order. It contains order lines that include ledger accounts, free-text descriptions, and a sales amount that you enter. You cannot enter an item number on this kind of invoice. You must enter the appropriate sales tax information. Also, the customer balance is posted to the summary account from the posting profile that is used for the free text invoice.
In addition, a free text invoice line can be used to sell a quantity of any kind of goods, services, or rights – providing unit price and quantity information to the customer. It also helps basic amount calculation, and it helps to better identify and explain charges to customers.
Now if we want to create a free text Invoice and post It. You have to follow this, Currently I am using
Contoso demo data and usmf legal entity.
Account receivable => common=> Free text Invoices => All free text Invoices
Free Text Invoice List page opens
Click on Free text Invoice, following form will open
Select the customer
Add invoice lines. And select main account, Sales tax group and Item sales tax group. Update the Unit price.
Now click on post on top menu
Following form will open
Click on ok button to post it, On successfully posting following form will open.