Scrapping of pdf invoices on E-commerce websites

we are an accounting firm, we have to collect for our clients their purchase invoices on different ecommerce websites like Amazon, Alibaba, Etsy..

Looking for someone able to scrap in python
Technology mastered: python, scrapping (either with the requests module, or with the Selenium module)
Difficulty: Captchas on the website login screen, usage of anti captcha services allowed