Askar Fuzaylov

$this->client->request('POST', $this->api_url, [
            'headers' => [
                'Content-Type' => 'text/xml;charset=UTF-8'
            ],
            'body' => $this->createRequestBody($request->to, $request->text)
        ]);

the OPENSSL_CONF environmental variable, if set, will be used as the path (including filename) of the configuration file.
the SSLEAY_CONF environmental variable, if set, will be used as the path (including filename) of the configuration file.
The file openssl.cnf will be assumed to be found in the default certificate area, as configured at the time that the openssl DLL was compiled. This is usually means that the default filename is c:\usr\local\ssl\openssl.cnf.

The database and PHP classes are now ready to be used. But they don't know yet how to communicate with each other at runtime. You must tell Propel which database connection settings should be used to finish the setup.