title: How to save a new address attribute in checkout
body: <p>I am trying to save geolocation along with the customer address.</p>
  <p>I have added Let &amp; Lng using the install script</p>
  <pre><code>    $customerSetup-&gt;addAttribute('customer_address', 'latitude', [
          'type' =&gt; 'varchar',
          'label' =&gt; 'Latitude',
          'input' =&gt; 'text',
          'required' =&gt; false,
          'visible' =&gt; true,
          'visible_on_front' =&gt; true,
          'user_defined' =&gt; false,
          'sort_order' =&gt; 43,
          'position' =&gt; 43,
          'system' =&gt; 0,
      ]);
  
      $attributeLat = $customerSetup-&gt;getEavConfig()-&gt;getAttribute('customer_address', 'latitude')
          -&gt;addData([
              'attribute_set_id' =&gt; $attributeSetId,
              'attribute_group_id' =&gt; $attributeGroupId,
              'used_in_forms' =&gt; ['adminhtml_customer_address', 'customer_address_edit', 'customer_register_address','customer_address'],
          ]);
      $attributeLat-&gt;save();
      //latitude - End
  
      $customerSetup-&gt;addAttribute('customer_address', 'longitude', [
          'type' =&gt; 'varchar',
          'label' =&gt; 'Longitude',
          'input' =&gt; 'text',
          'required' =&gt; false,
          'visible' =&gt; true,
          'visible_on_front' =&gt; true,
          'user_defined' =&gt; false,
          'sort_order' =&gt; 43,
          'position' =&gt; 43,
          'system' =&gt; 0,
      ]);
  
      $attributeLng = $customerSetup-&gt;getEavConfig()-&gt;getAttribute('customer_address', 'longitude')
          -&gt;addData([
              'attribute_set_id' =&gt; $attributeSetId,
              'attribute_group_id' =&gt; $attributeGroupId,
              'used_in_forms' =&gt; ['adminhtml_customer_address', 'customer_address_edit', 'customer_register_address','customer_address'],
          ]);
      $attributeLng-&gt;save();
      //longitude - End}
  </code></pre>
  <p>I can update values in the admin backend without an any issue.</p>
  <p>In the checkout page form fields for &quot;latitude&quot; &amp; &quot;longitude&quot; are appearing. But values don't save along with the customer address.</p>
  <p>I am using Magento CE 2.2.3</p>