LWC Challenge component 3 (inspired from https://github.com/trailheadapps/lwc-recipes/tree/master/force-app/main/default/lwc/apexWireMethodWithParams)

component3.html

<template>
    <lightning-card
    title="Christmas gift ideas for children"
    icon-name="custom:custom57"
>
    <div class="slds-var-m-around_medium">
        <lightning-input
            type="search"
            onchange={handleKeyChange}
            class="slds-show slds-is-relative slds-var-m-bottom_small"
            label="Search"
        ></lightning-input>
        <template if:true={gifts}>
            <template for:each={gifts} for:item="gift">
                <li key={gift.Id}>
                {gift.Name}
            </li>
            </template>
        </template>
    </div>
  
</lightning-card>  
</template>

component3.js

// Inspired from LWC recipes 
// https://github.com/trailheadapps/lwc-recipes/tree/master/force-app/main/default/lwc/apexWireMethodWithParams

import { LightningElement, wire, api  } from 'lwc';
import findGifts from '@salesforce/apex/GiftController.findGifts';

/** The delay used when debouncing event handlers before invoking Apex. */
const DELAY = 350;

export default class Component3 extends LightningElement {

    gifts;
    error;

    handleKeyChange(event) {
        // Debouncing this method: Do not actually invoke the Apex call as long as this function is
        // being called within a delay of DELAY. This is to avoid a very large number of Apex method calls.
        window.clearTimeout(this.delayTimeout);
        const searchKey = event.target.value;
        // eslint-disable-next-line @lwc/lwc/no-async-operation
        this.delayTimeout = setTimeout(() => {
            findGifts({ searchKey })
                .then((result) => {
                    this.gifts = result;
                    this.error = undefined;
                })
                .catch((error) => {
                    this.error = error;
                    this.gifts = undefined;
                });
        }, DELAY);
    }

}

GiftController.cls

ublic with sharing class GiftController {
    
    @AuraEnabled(cacheable=true)
    public static List<Cadeau__c> findGifts(String searchKey) {

        String str = 'SELECT Id,Name FROM Cadeau__c where ((publicCible__c = \'Enfant\') and Name like \'%' + searchKey + '%\')' ;
      
       return Database.query(str);