src/Upwork/API/AuthTypes/OAuth1.php
protected function _setupAccessToken($verifier)
    {
        ApiDebug::p('requesting access token');

        $oauth = $this->_getOAuthInstance(OAUTH_AUTH_TYPE_FORM);
        $oauth->setToken(self::$_requestToken, self::$_requestSecret);
        $accessTokenInfo = $oauth->getAccessToken(
            ApiUtils::getFullUrl(self::URL_ATOKEN, 'api'),
            null,
            $verifier
        );

        ApiDebug::p('got access token info', $accessTokenInfo);

        self::$_accessToken     = $accessTokenInfo['oauth_token'];
        self::$_accessSecret    = $accessTokenInfo['oauth_token_secret'];

        return $accessTokenInfo;
    }
protected function _setupAccessToken($verifier)
    {
        ApiDebug::p('requesting access token');

        $oauth = $this->_getOAuthInstance(OAUTH_AUTH_TYPE_FORM);
        $oauth->setToken(self::$_requestToken, self::$_requestSecret);
        $accessTokenInfo = $oauth->getAccessToken(
            ApiUtils::getFullUrl(self::URL_ATOKEN, 'api'),
            null,
            $verifier
        );

        ApiDebug::p('got access token info', $accessTokenInfo);

        self::$_accessToken     = $accessTokenInfo['oauth_token'];
        self::$_accessSecret    = $accessTokenInfo['oauth_token_secret'];

        return $accessTokenInfo;
    }
Get access token

@param	string $verifier OAuth verifier, got after authorization
@access	protected
@return	array