Try this;
First of all your firmware must be 11.4 and higher.
Location of Luma Plugin Loader's boot.firm (the boot.7z file from OP post) goes to;
CTRPF Action Replay (the ActionReplay.7z from OP post) goes to;
- SD: /luma/plugins/ActonReplay/ActionReplay.plg
Your txt file goes to;
- SD; /cheats/<Title ID of the game>.txt
Example;
Cheat txt file for the game MHXX;
- SD; /cheats/0004000000197100.txt
When you did all that enable the Plugin Loader from Rosalina Menu (L+DOWN+SELECT to open Rosalina Menu).
Then launch your game, when there's a Green flash on screen, then it works. Press SELECT to open the plugin.
NOTES:
All folder and files' name are case-sensitive.
Extract the .7z files first.
You don't have to launch BootNTR.