Kindle I pad

If you used the same AmazonID and password on both

kindles and your content did not download, reach out

to Amazon/Kindle for assistance.

This link may give you a start:

https://www.amazon.com/gp/help/customer/display.html?nodeId=200127470

If this is not what you are asking, provide more information

so someone may offer a solution.

Kindles are made by Amazon.

They aren’t an Apple product.

The kindle app on Apple devices is Amazon’s app.

They are responsible for the app functions and services.

Contact Amazon.