First, you will need to create a LWC component that queries the Account object and retrieves the accounts. You can use the @wire decorator to wire the component to the Apex method that retrieves the accounts.

import { LightningElement, wire } from 'lwc';
import { getObjectInfo } from 'lightning/uiObjectInfoApi';
import { getRecord } from 'lightning/uiRecordApi';
import getAccounts from '@salesforce/apex/AccountController.getAccounts';

export default class TopAccounts extends LightningElement {
    @wire(getAccounts) accounts;
}
 

Then, in the Apex class, you can create a method called getAccounts which queries the accounts and sorts them by the amount field in descending order. You can use the LIMIT clause to retrieve only the top 3 accounts.

public with sharing class AccountController {
    @AuraEnabled(cacheable=true)
    public static List<Account> getAccounts() {
        return [SELECT Id, Name, Amount__c FROM Account ORDER BY Amount__c DESC LIMIT 3];
    }
}
 

Finally, in the HTML template of the component, you can use a template for:each to iterate over the accounts and display the top 3 accounts with the highest amount.
<template>
    <template if:true={accounts.data}>
        <template for:each={accounts.data} for:item="account">
            <div key={account.Id}>
                <p>{account.Name} - {account.Amount__c}</p>
            </div>
        </template>
    </template>
</template>

Goodluck