Fire HD 8 / 10 2015 (thebes and memphis) for /e/OS-Nougat 0.21
e-0.21-n-20241110-UNOFFICIAL-thempis.zip
https://sourceforge.net/projects/eosbuildsronnz98/files/OtherSmartphones/e-0.21-n-20241110-UNOFFICIAL-thempis.zip/download
Please see sources and install instructions including recovery here:
https://xdaforums.com/t/rom-unofficial-7-1-2-lineageos-14-1-for-amazon-fire-hd8-10-thebes-memphis.4702107/
Use it at your own risk!
Please support the developer(s)!