All you need to do is use your channel url with /mrss?rowCount=100 added to the end of it.
EXAMPLE:
https://www.joshwhotv.com/channel/SeekingTheTruth/mrss?rowCount=100Use that link for your amazon app make sure to update it to your channel name and it is case sensitve so make sure it is your channel URL.
This will also work with KODI and other apps that can read MRSS feed format.