Hi, I develop under odoo 15. 

I have already created a module of entities "entities" management (Customers, Vondors, Products, ...), and now I am creating an invoincing "invoice" module.

For the moment, in the "invoice" module, I have created a model "invoice_temporary.py" to collect all the data needed for an invoice from the "entities" models.

So now I plan to create the real invoice (which respects the condition of inalterability) from the "invoice_temporary" model.

With this model, I have all the data needed for the real invoice, so I ask here :

"How can I create an inalterable invoice from a simple model ?"

"Should I create the invoice in another way ?"

Thanks in advance, I tried to be as clear as possible,

Hugo