Trying to access array offset on value of type null

[Axel-AMGHAR]

• BotMan Version: 2.6.1
• PHP Version: 7.4.25
• Messaging Service(s):
• Cache Driver:
• FacebookDriver: 1.11.0

Description:

Error when calling chatbot with FacebookDriver:

local.ERROR: Trying to access array offset on value of type null {"exception":"[object] (ErrorException(code: 0): Trying to access array offset on value of type null at .......vendor/botman/driver-facebook/src/FacebookDriver.php:516)

So in FacebookDriver:
$facebookResponse->getContent() return nothing
$facebookResponse->getStatusCode() = 500

protected function throwExceptionIfResponseNotOk(Response $facebookResponse)
{
    if ($facebookResponse->getStatusCode() !== 200) {
        $responseData = json_decode($facebookResponse->getContent(), true);
        throw new FacebookException('Error sending payload: '.$responseData['error']['message']);
    }
}

Steps To Reproduce:

Facebook driver tutorial