https://developer.fortnox.se/documentation/resources/invoices/ - an example of how requests are described
Create an invoice
The created invoice will be returned if everything succeeded, if there was any problems an error will be returned.
You must specify a customer to create an invoice. It's possible to create an invoice without rows, although we encourage you to add them if you can.
Predefined values will be used for properties where it applies, the values can be changed in the settings for the Fortnox account. Predefined values will always be overwritten by values provided through the API.
Examples
CURL
PHP
RUBY
PYTHON
C#
Request
curl -X "POST" "
https://api.fortnox.se/3/invoices" \
-H "Access-Token: 61cf63ae-4ab9-4a95-9db5-753781c4f41f" \
-H "Client-Secret: 3Er4kHXZTJ" \
-H "Content-Type: application/json" \
-H "Accept: application/json" \
-d $'{
"Invoice": {
"CustomerNumber": "100",
"InvoiceRows": [
here it is clear what needs to be passed in the headers, what is in the body.yu and what format of the request body
can we get a similar example or not?