External API auth should be a ServiceProvider or Controller in Laravel?

Im building a shopify app using Laravel, that app will allow the users to connect there Shopify shop with a third party email marketing software, When the app user go to the homepage he will get asked for key/secret token for that email marketing API to autorize the connection using OAUTH then the the access token will get stored in database for future use. later using that access token i should be able to use api to post or get contacts from and to the customer email marketing account by using

Hello, Im building an app using Laravel, that app will allow the customers to send and get contacts from/to Mautic (email marketing software) via API, but first the app need to get an autorization to use Mautic API and store the user credintals to database for future use.

This is an example for how i make an autorization to connect to that api

$settings = [
    'userName'   => '',             // Create a new user       
    'password'   => '',             // Make it a secure password
];

// Initiate the auth object specifying to use BasicAuth
$initAuth = new ApiAuth();
$auth     = $initAuth->newAuth($settings, 'BasicAuth');

and then i can get the contact by id using this

$api        = new MauticApi();  //This class is from the API package
$contactApi = $api->newApi('contacts', $auth, $apiUrl);
$response = $contactApi->get($id);

So my question is how can i organize that logic, should i just put all of it in a controller or it's better to create a service provider which should be responsible of the autorization and then return $auth handle that i can use then later for each customer, and if it's better to user the serviceprovider approch then i'm wondering how can i do that, should i just put the autorization logic in the boot method?

via Chebli Mohamed