Integrating Contact Form 7 with third-party app - wordpress

Question

I am trying to send information from user submissions (Contact Form 7) to third-party app. I am using this plugin
https://wordpress.org/support/plugin/cf7-to-api/
The third-party app provided an access token and this example of creation request for me
curl -X "POST" "https://api.example.com/initial-params" \
-H 'Content-Type: application/json' \
-H 'X-Landing-Page-Access-Token: your-value-here ' \
-d $'{
"move": {
"date": "2018-09-01"
},
"consumer": {
"givenName": "Mike",
"phone": "234234242",
"email": "mike#example.com",
"familyName": "Simon"
},
"origin": {
"zip": 3245,
"beds": 8
},
"destination": {
"zip": 12342
}
}'
and this is their documentation
An end consumer enters details onto a landing page. Once all details have been entered, the landing page POSTs to our API's Initial Params endpoint. Our app stores the parameters and generates a unique identifier. Once the API call to create Initial Params succeeds, the landing page automatically redirects to the survey web app with the identifier set as a URL parameter (e.g., ?identifier=xxx... )
- Important : Our survey web app must have received this import in order for follow-up
messaging to work if the consumer drops off. As a result, it is recommended to automatically
redirect to our survey web app after the Initial Params have been created as opposed to
requiring a button click.
When our survey web app loads, it queries our API to retrieve the parameters. With the
parameter information, it then initializes the survey web app and API to the state specified in the
Initial Parameters. Each screen that has input completely satisfied is automatically skipped. The consumer finishes the process on our survey web app. One this identifier has been generated, the landing page can redirect to our survey web app. This identifier should be passed along to our survey web app via the identifier URL parameter, which will in turn allow the provided consumer details to be loaded inside our app. Example link: https://api.example.com/?identifier=xxx
This is a creation response example the third-party app also provided
HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Type: application/json
Date: Wed, 18 Jul 2018 16:55:04 GMT
Server: nginx
Content-Length: 380
Connection: Close
{
"status": [
{
"type": "ok"
}
],
"identifier":
"some-unique-identifier",
"serverTime": "247.334 ms"
}
So, I used this https://api.example.com/initial-params as the URL to post to, added the access token using this piece of code in functions.php
add_filter( 'qs_cf7_api_get_args', 'add_http_header' );
function add_http_header( $args ) {
$args['headers']['X-Landing-Page-Access-Token'] = 'example-access-token';
return $args;
}
and I used this in the JSON template
-d $'{
"move": {
"date": "[date]"
},
"consumer": {
"givenName": "[givenName]",
"phone": "[phone]",
"email": "[email]",
"familyName": "[familyName]"
},
"origin": {
"zip": [zip1]
},
"destination": {
"zip": [zip2]
}
}'
My questions are:
How can I check the result I get from them, to see if they are receiving the info and generating the identifier?
How to redirect to their landing page with the identifier in the end when a form is submitted? That identifier is a variable and is unique each time, which means somehow I have to redirect to a variable after submission.
Any help is much appreciated.
Thank you!