On getBody(), I needed to run getContents(), like:
echo $response->getBody()->getContents()
// {"access_token":"sdoginGDpng3pnGPNGDDGGDP))","expires":86399}
On getBody(), I needed to run getContents(), like:
echo $response->getBody()->getContents()
// {"access_token":"sdoginGDpng3pnGPNGDDGGDP))","expires":86399}