Step 1: Download NotoSansKannada Fonts on your computer
Step 2: Connect your Kindle Device* using USB. Don’t eject.
Step 3: Open Kindle Folder
Step 4: Create ‘fonts’ directory, and copy ‘NotoSansKannada.ttf’ inside of it.
Step 5: Create an empty file named ‘USE_ALT_FONTS’ (Note: without any file extensions),
at the root (ie, inside ‘Kindle’ directory level).
Step 6: Eject Kindle from Computer.
Step 7: Reboot kindle.
Now, you can read Kannada books inside Kindle, without issues.
‘*’ — Supported Kindle devices are shown in below image. Note that software version
may change in the same.