use NgLam2911\InvCraft\crafting\Recipe;
use NgLam2911\InvCraft\InvCraft;

$recipeManager = InvCraft::getInstance()->getRecipeManager();
// Create a new recipe
$recipe = new Recipe(<args here>);
$recipeManager->addRecipe($recipe);
// Remove a recipe
$recipeManager->removeRecipe(<recipe name>);
// Get a recipe
$result = $recipeManager->getRecipe(<recipe name>);

use NgLam2911\InvCraft\event\InvCraftItemEvent;

// EventsListener.php
public function onCraft(InvCraftItemEvent $event) {
    $player = $event->getPlayer();
    $recipe = $event->getRecipe();
    $result = $event->getResult();
    // Do something here
}