Power BI : Connecting to AWS S3 Billing REST APIs

Hi, I need to develop AWS billing dashboard for which our team stores data in CSV files in AWS S3 bucket. After some research on Power BI Community, I understand there are two ways to connect.

1. Through zappysys S3 csv driver : Since its a licensed utility, I can't go with it

2. By connecting AWS S3 billing REST APIs via Web Connector and parse JSON response

I went through many articles which are listed below but didn't found any practical information where demonstration of Power BI connecting to S3 buckets via Web connector is done. Can someone please post a step by step tutorial here which can be used in the future for everyone. 

References I have gone through : 
https://community.powerbi.com/t5/Power-Query/Can-I-connect-to-a-Amazon-S3-bucket-using-Power-Query/td-p/111919
https://community.powerbi.com/t5/Service/Power-BI-Web-App-and-AWS-S3/td-p/617949#:~:text=It%20is%20not%20possible%20to,in%20Power%20BI%20web%20connector.

https://community.powerbi.com/t5/Power-Query/Pull-data-from-a-REST-API-Authentication/td-p/246006

Please help. Greg_Deckler amitchandak