how to include saved value in the next stage request url

[colinshin]

We have a service with the URL, https://www.domain.com/parallel/tests/uuid
I would like to run the test stage(name: Verify tests get API) with the saved value newtest_uuid
How can I use newtest_uuid in the second stage?

includes:
  - !include includes.yaml
stages:
  - name: Verify tests post API
    request:
      url: "{HOST:s}/parallel/tests/"
      method: POST
      json:
        name: 'co-test-9'
        apptype: 'parallel'
        user: 'wangxi'
        product: 'centos'
        build : 'ob-123'
        resolution: '1600x1200'
        start_url: 'https://www.github.com/'
        locales: "['192.168.0.1']"
    response:
      strict:
        - json:off
      status_code: 200
      save:
        json:
          newtest_uuid: "testcase.uuid"

  - name: Verify tests get API
    request:
      url: "{HOST:s}/parallel/tests/{newtest_uuid}"
      method: GET
    response:
      strict:
        - json:off
      status_code: 200

I did this, but it doesn't work, and got errors

  - name: Verify tests get API
    request:
      url: !force_format_include"{HOST}/parallel/tests/{newtest_uuid}"
      method: GET
    response:
      strict:
        - json:off
      status_code: 200

How can i use the saved newtest_uuid in the second stage?
Thanks

[colinshin]

use like below

  - name: Verify tests get API
    request:
      url: "{HOST:s}/parallel/tests/{newtest_uuid:s}"
      method: GET
    response:
      strict:
        - json:off
      status_code: 200

I got error

to_format = '{HOST:s}/parallel/tests/{newtest_uuid:s}'
box_vars = <Box: {'HOST': 'http://127.0.0.1:9000', 'TESTCASE_ID': '5087', 'SCRIPT_ID': '5863', 'PARALLEL_TEST_UUID': '7cd9...RENT_TEST': 'parallel/test_04_update_tests.tavern.yaml::Make sure tests api functions (call)'}}, 'newtest_uuid': None}>

newtest_uuid is None

[colinshin]

iit works like below

  - name: Verify tests get API
    request:
      url: "{HOST:s}/parallel/tests/{newtest_uuid}"
      method: GET
    response:
      strict:
        - json:off
      status_code: 200