How to Sync Notes & Highlights from Kindle Account to iOS / Android Apps - Similar to what ReadWise does

Question

I've been researching for ways in which I could fetch Notes & Highlights from my Kindle Account to an iOS/Android App.

Things I know so far

1. There is no official Kindle API which Amazon provides, at the moment (Sep 2021)
2. There are few ways in which I could achieve this functionality but most of them are from Web-Scraping in which I would have to explicitly provide email address and password for the Amazon account for accessing highlights from Kindle Highlights Url
3. There are few git projects which already help with web-scraping but again, we have to explicitly provide email address and password

• PHP : https://github.com/johnpaulhayes/Kindle-Highlights
• Ruby : https://github.com/kyamaguchi/kindle_manager
• Ruby : https://github.com/speric/kindle-highlights

4. There are few official app which have this functionality of syncing all the highlights from Kindle to the app but I'm not sure how they achieve this

• ReadWise : https://readwise.io
• Calibre : https://calibre-ebook.com
• clippings.io : https://www.clippings.io

So just to summarise my question. I'm looking for a way to access Kindle Highlights & Notes from my kindle account directly to my app both in iOS and Android.

From the examples above, I know its possible but not sure how to go about implementing it.

Any help would be appreciated

Preoccupied