SAP ByDesign Front End Debugger is great tool to find out field names and more from the front end.
Get this URL and change tenant to your tenant: https://my3xxxx2.sapbydesign.com/sap/public/ap/ui/repository/SAP_UI/HTML5/client.html?debugMode=true&app.component=/SAP_UI_CT/Main/root.uiccwoc&rootWindow=X&redirectUrl=/sap/public/byd/runtime
Go to the work center of where you want to know the information from. For example I go to Sales Quotes->General and I want to know the backend name for the ShipToParty field.
Ctrl+left click on the field and you will get this popup:
From the Component Model XML you will be able to see the technical name for the field.
This debugging info has much more valuable information regarding the screens and OWL elements etc.
Hope its useful!