I have a problem to link to other url when I click image by using Vue.

It suppose to be able to link by clicking images but it does not work.

If there are anyone who can help me I am very appreciated. 

My code looks like below.

HTML

```
<section class="bg-light page-section" id="portfolio">
    <div class="container">
      <div class="row">
        <div class="col-lg-12 text-center"><br>
          <h2 class="section-heading text-uppercase works-text">Works</h2>
          <h3 class="section-subheading text-muted">Selected work that has been created with the help of many.</h3>
        </div>
      </div>
      <div class="row">
       <div class="col-md-4 col-sm-6 portfolio-item" v-for="(obj, key) in portfolioJSON" :key="key"  >
          <a class="portfolio-link" data-toggle="modal" target = "_blank" v-bind:href="`${obj.url}`">
            <div class="portfolio-hover">
              <div class="portfolio-hover-content">
                <!-- <! <i class="fas fa-plus fa-3x"></i> -->
              </div>
            </div>
            <img :src="`${obj.img}`" class="img-fluid" >
          </a>
          <div class="portfolio-caption works-text">
            <h4 class="works-text">{{ obj.caption }}</h4>
            <p class="text-muted works-text">{{ obj.title }}</p>
          </div>
        </div>

      </div>
    </div>
  </section>

```

```
export default {
    data() {
      return{
        portfolioJSON: [
           {
                img: require('../assets/img/sukimatch/sukimatch.png'),
                caption: 'Sukimatch',
                title: 'WEBSITE, BANNER DESIGN',
                url: "https://sukimatch-f887f.firebaseapp.com/"
            },
            {
                img: require('../assets/img/portfolio/greencosjapan.png'),
                caption: 'Greencosjapan',
                title: 'WEBSITE',
                url: "https://greencosjapan.com"
            }
        ]
    }
    }, computed: {
    imageArray: function() {
        return this.portfolioJSON.map(obj => obj.img)
    },
    urlArray: function() {
        return this.portfolioJSON.map(obj => obj.url)
    }
},

}

```