Simple Website + Backend in AWS refreshing data from Fortnox

Create a service that makes it easy for the customers to access their financial data using Power BI and Excel.

Create a very simple website that:
1. Can be signed into and add necessary details for accessing Fornox
Create a service on AWS that:
1. Stores data from Fortnox and refreshes every day
2. Is accessible from Power BI & excel

This will then be used by different companies to analyze their finances in Excel and PowerBI. This will be sold as a subscription service.

Please answer with:
1. A suggested high-level solution in AWS
2. Your experience with the proposed AWS services in the solution