I am using SmartAccounts accounting software for 2 of my companies. They offer among others option for API integrations.

One of the most common use cases for e-commerce sites to have API integration with accounting software is to generate sales invoices in accounting software. Sales invoices need to end up there anyway and unless you have really cheap accountant then I recommend having it being done automatically. Especially because SmartAccounts and WooCommerce plugin is free to use.

Since WooCommerce was lacking simple plugin for sending sales invoices to SmartAccounts accounting software over API integration then I published it myself in Github as well as in WordPress plugin portal.

This plugin is also featured in SmartAccounts own website https://www.smartaccounts.eu/et/abimaterjalid-ja-klienditugi/liidetud-teenused/woocommerce-plugin/