Lexoffice: Missing input

Hi, I use lexoffice module to create invoices. However, in this module, I am missing the endpoints “totalDiscountAbsolute” and “totalDiscountPercentage” to add a discount to the invoice.
Can I expand the outgoing api call by these endpoints?
Or who is the right person to extend this module?

u need api to add this value

Well yes. But I am struggling with this. I try to use “create JSON” module and connect it with “lex api” module. In “create JSON” I put in sample data from a working create invoice call, and it builds the needed structure. But after mapping the line items coming from a woocommerce order, the lex api responds “[400] Invalid value ‘1038’ for ‘lineItems[0].id’. Value of type UUID expected.”

you need to iterate lineitem first before putting in your json payload of api

The error alo occurs if I put in one line item manually. So no mapping or iterating.
But I also cannot put the format of the id to UUID.

So can you help me with this data type UUID?