Refresh Token, Resource Owner not getting sent back

[Doug Black]

I am calling the OAuth function and getting a successful access token. However, when using the ->getRefreshToken() function, I am not getting anything back and it is coming back null.

Controller function

if($code = request()->get('code')) {

	try {

		// Try to get an access token using the authorization code grant.
		// We have an access token, which we may use in authenticated
		// requests against the service provider's API.
		// 'Access Token: ' . $accessToken->getToken()
		// 'Refresh Token: ' . $accessToken->getRefreshToken()
		// 'Expired in: ' . $accessToken->getExpires()
		// 'Already expired? ' . $accessToken->hasExpired()

		$accessToken = $this->provider->getAccessToken(
			'authorization_code',
			[
				'code' => request()->get('code'),
			]
		);

		$resourceOwner = $this->provider->getResourceOwner($accessToken);

		$data = [
			'access_token'	=> $accessToken->getToken(),
			'refresh_token' => $accessToken->getRefreshToken(),
			'expires'		=> Carbon::parse($accessToken->getExpires()),
			'resource_owner'	=> json_encode($resourceOwner),
			'data'				=> [
				'instance_url'	=> $accessToken->getInstanceUrl(),
			]
		];

		$userResource = UserResource::updateOrCreate(
			[
				'type'			=> 'salesforce',
				'user_id'		=> Auth::id(),
			],
			$data
		);

		event(new AccessTokenAdded($userResource));

		return redirect(config('salesforce.redirect_url') . '?success=true');

	} catch (IdentityProviderException|ErrorException|Exception $e) {

		// Failed to get the access token or user details.
		$message = json_encode([
			$e->getMessage(),
		]);

		return redirect(config('salesforce.redirect_url') . '?success=false');
	}

} else {
	$loginUrl = 'https://login.salesforce.com/services/oauth2/authorize'
				. '?response_type=code&client_id=' . config('salesforce.client_id')
				. '&redirect_uri=' . config('salesforce.callback_url');

	return redirect($loginUrl);
}

The response data ($data variable in example above) looks like this:

{
  "access_token": "reallylongtoken",
  "refresh_token": null,
  "expires": "2020-12-15T12:21:57.060855Z",
  "resource_owner": "{}",
  "data": {
    "instance_url": "https://mycustomdomain.my.salesforce.com"
  }
}