I’m having trouble using REST API to get a list of all the Invoices generated for a sales order. Also, is there a way to have REST Generate a PDF version of the invoice that could be downloaded? Any help would be appreciated, this one has me stuck!
For that you want to use a BAQ.
Also for generating a PDF Version see this
https://www.epiusers.help/t/trigger-arinvoice-generation-from-api-not-totally-getting-it