Hello Geetha A 2
Please find the solution.
First you have to store the image in static resourse:-

staticResourceLWCExample.html
 

<template>
  <lightning-card title="Static Resource Example LWC" icon-name="custom:custom19">
      <div class="slds-m-around_medium">
          <img src={yin} download>
      </div>
      
    <div>
        <a href={url} onclick={handleClick} download="">Download</a>
    </div>

  </lightning-card>
</template>

import { LightningElement } from 'lwc';
import My_Resource from '@salesforce/resourceUrl/yin';
import { NavigationMixin } from 'lightning/navigation';
export default class StaticResourceLWCExample extends NavigationMixin(LightningElement) {
    yin = My_Resource;
     url;

    

    handleClick(evt) {
       this.url="https://power-agility-6120-dev-ed.lightning.force.com/resource/1638705339000/yin";
    }
}

<?xml version="1.0" encoding="UTF-8"?>
<LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata">
    <apiVersion>48.0</apiVersion>
    <isExposed>true</isExposed>
    <targets> 
        <target>lightning__AppPage</target>
        <target>lightning__RecordPage</target>
        <target>lightning__HomePage</target>
    </targets>
</LightningComponentBundle>