Authorize to a 3rd party service within Postman request - api

Question

Want to create request in Postman to cover authorization to a 3rd party within request. In application it works this way:
Client clicks the button
Application checks whether there is a token, if not it returns link to the 3rd party service to authorize there
Client follows the link, inputs credentials, submits form
Service redirects client back to the application with authorization code as a query parameter.
Client pushes another button to receive token by the authorization code.
So, is there a way to proceed this scenario within the Postman, not to copy link from response and pasting it to browser in order to complete authorization?
Tried to make request from Test script tab like:
var jsonData = JSON.parse(responseBody);
console.log(jsonData.data)
if (jsonData.data) {
pm.sendRequest(jsonData.data, function (err, response) {
console.log(response);
return response;
});
}
But that was not actually useful

Answer 1

There is a way to get token before request.
You can use Pre-request Script bookmark.
Write JS code to get token and save it to variable (collection / environment).
In specific request open Authorization bookmark and call your variable.
For Bearer:
My Pre-Request Script for example:
let collUsername = pm.variables.get("username");
let collPassword = pm.variables.get("password");
let collClient_id = pm.variables.get("client_id");
let collClient_secret = pm.variables.get("client_secret");
const postRequest = {
url: pm.variables.get("url"),
method: 'POST',
header: {
'Accept': '*/*',
'Content-Type': 'application/x-www-form-urlencoded'
},
body: {
mode: 'urlencoded',
urlencoded : [
{ key: 'username', value: collUsername},
{ key: 'password', value: collPassword},
{ key: 'grant_type', value: 'password'},
{ key: 'client_id', value: collClient_id},
{ key: 'client_secret', value: collClient_secret},
{ key: 'user_type', value: 'System'}
]
}
};
pm.sendRequest(postRequest, (error, response) => {
console.log(error ? error : response.json());
let jsonRes = response.json();
pm.collectionVariables.set("token", jsonRes.access_token);
});
I don't know your authentication method so your script can be different.
If you want to refresh only expired token you can add variable with date and check if appropriate time has passed to get new token.
Edit: Scripts written in Tests are executed after getting response so not proper place for your case.