LinkedIn API OAuth refresh token - php

Question

I am using LinkedIn API to pull updates from there and display on the website. While using OAuth, I am storing the token in a file and then pull it from there again to prevent the login popup. However, I am not clear once my token expires how will it get refreshed. Following is how I am reading the token from the file -
$config = json_decode(file_get_contents(".service.dat"));
if( isset($config->key) && isset($config->secret) ) {
$this->access_token = new OAuthConsumer($config->key, $config->secret);
}
For authentication I have following to get request token -
function getRequestToken()
{
$consumer = $this->consumer;
$request = OAuthRequest::from_consumer_and_token($consumer, NULL, "GET", $this->request_token_path);
$request->set_parameter("oauth_callback", $this->oauth_callback);
$request->sign_request($this->signature_method, $consumer, NULL);
$headers = Array();
$url = $request->to_url();
$response = $this->httpRequest($url, $headers, "GET");
parse_str($response, $response_params);
$this->request_token = new OAuthConsumer($response_params['oauth_token'], $response_params['oauth_token_secret'], 1);
}
After generating token, I am generting authorize url:
function generateAuthorizeUrl()
{
$consumer = $this->consumer;
$request_token = $this->request_token;
return $this->authorize_path . "?oauth_token=" . $request_token->key;
}
LinkedIn documentation states following about refresh token:
Refreshing an access token is very simple and can happen without an
authorization dialog appearing for the user. In other words, it's a
seamless process that doesn't affect your application's user
experience. Simply have your application go through the authorization
flow in order to fetch a new access token with an additional 60 day
life span.
I am not clear what that means. If I have to redo all the way from obtaining request token again then wouldn't that require me to make http request again and having to popup the login screen? How do I avoid it? Will appreciate suggestion.
Thanks.

Answer 1

Found out. Authorization URL:
https://www.linkedin.com/oauth/v2/authorization
followed by the access token url:
https://www.linkedin.com/oauth/v2/accessToken
was all that I really had to do (passing with the right parameters).

Answer 2

There is also a endpoint to refresh the token once it expire, here is the documentation of the way to do it: https://learn.microsoft.com/en-us/linkedin/shared/authentication/programmatic-refresh-tokens

Answer 3

If You go through the documentation
Linkedin does not provide refresh token you need to again go through the workflow.
Here is the Short Explanation:
To refresh an Access Token, simply go through the authorization process outlined in this document again to fetch a new token. During the refresh workflow, provided the following conditions are met, the authorization dialog portion of the flow is automatically skipped and the user is redirected back to your callback URL, making acquiring a refreshed access token a seamless behind-the-scenes user experience
Refresh your Access Tokens