Retrieve a label dynamically in LWC

label.app

<aura:application extends="force:slds">
    <c:q317434 />
</aura:application>

label.app-meta.xml

<?xml version="1.0" encoding="UTF-8"?>
<AuraDefinitionBundle xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>54.0</apiVersion>
    <description>Container for Dynamic Labels in LWC</description>
</AuraDefinitionBundle>

label.cls

public class label {
	@AuraEnabled(cacheable=true) public static String getLabel(String label) {
        PageReference pageRef = Page.label;
        pageRef.getParameters().put('label', label);
        return pageRef.getContent().toString();
    }
}

label.cls-meta.xml

<?xml version="1.0" encoding="UTF-8"?>
<ApexClass xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>54.0</apiVersion>
    <status>Active</status>
</ApexClass>

label.page

<apex:page sidebar="false"
           showChat="false" 
           showHeader="false" 
           applyBodyTag="false" 
           applyHtmlTag="false"
           contentType="application/json"
           language="{!$CurrentPage.parameters.lang}">{
    "value": "{!JSENCODE($Label[$CurrentPage.Parameters.label])}"
}</apex:page>

label.page-meta.xml

<?xml version="1.0" encoding="UTF-8"?>
<ApexPage xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>49.0</apiVersion>
    <availableInTouch>false</availableInTouch>
    <confirmationTokenRequired>false</confirmationTokenRequired>
    <label>label</label>
</ApexPage>

q317434.html

<template>
    <lightning-input label="Source"></lightning-input>
    <lightning-button label="Get Label" onclick={handleClick}></lightning-button>
    {outputLabel}
</template>

q317434.js

import { LightningElement } from "lwc";
import getLabel from "@salesforce/apex/label.getLabel";

export default class Q317434 extends LightningElement {
  outputLabel;
  async handleClick(event) {
    try {
      const label = this.template.querySelector("lightning-input").value;
      this.outputLabel = JSON.parse(await getLabel({ label })).value;
    } catch (e) {
      this.outputLabel = "**Unknown**";
    }
  }
}

q317434.js-meta.xml

<?xml version="1.0" encoding="UTF-8"?>
<LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>52.0</apiVersion>
    <isExposed>false</isExposed>
</LightningComponentBundle>