Show Variant metafield value on frontend.

[ankurlighting]

Hi, I am trying to show variant metafield value on frontend. I used following code to show it 

              {% if variant.metafields.dimension_details.variant_length != blank %}
              <tr>
                <th class="attr__label">Length</th>
                <td class="attr__value">
                <p>{{variant.metafields.dimension_details.variant_length}}MM</p>
                </td>
              </tr>
              {% endif %}

I have already added the values in metafield. But on frontend, metafield value is not showing.