I can highly recommend easybits for data extraction. It’s super easy to set up and can be implemented directly via API through an HTTP node. You can find a step-by-step integration guide here: Extract Structured Data from Documents in Minutes
If you need any help, feel free to reach out. I’ve also created a workflow that does exactly what you’re trying to achieve, but it uses Telegram as the interface, allowing you to upload PDF files or photos directly through the chat. You can find the workflow here: Automated expense tracking with Telegram, easybits & Google Sheets | n8n workflow template