title: django rest framework access item by lookup field instead of pk 3.4 DRF
body: <p>I need to have lookup field in order my frontend sends email which should be deleted but I get item not found. I've researched a lot about this problem but I can't figure out which DRF version what supports.</p>
  
  <pre><code>class EmailReminderSerializer(serializers.ModelSerializer):
      city = serializers.CharField(max_length=255)
      url = serializers.HyperlinkedIdentityField(
          view_name='web:email_reminder-detail',
      )
  
      class Meta:
          model = EmailReminder
          fields = '__all__'
          extra_kwargs = {
              'url': {'lookup_field': 'email'}
          }
  </code></pre>
  
  <p>Now I have url but it points to instance pk, not by my desired lookup field.
  Any suggestions of how it works in 3.4 version or do you have any other solutions to some lower version >=3.0?</p>