Document Creation

Hello everyone I would like to create a screen for the creation of documents such as invoices, transport, returns etc etc…
in detail there should be a main part where you enter the customer details and a secondary part where you enter the details of the lines with the ability to search for products to be entered, I tried to see dymic-form, but when you then have to do some operations on the fields in detail (calculations or return the description of a product), it does so only in the first line.
Does anyone know if there is another method or do you have examples I can draw on?
Thank you all