Local QR Code Generation

In terms of security we'd like to cut off our teampass server from accessing internet. But this would disable  QR code generation for Google Authenticator (we preferred to use this one).

Is there any way to modify GoogleQRCodeProvider to maybe:
1. use qrencode ubuntu package and generate imagefiles or
2. generate using phpqrcode.ph/qrlib.php library

I have zero expertise on PHP but im guessing changes can be made in GoogleQRCodeProvider.php . Please enlighten thy poor soul.

public function getQRCodeImage($qrtext, $size)
{
return $this->QRcode::png(rawurlencode($qrtext))
// return $this->getContent($this->getUrl($qrtext, $size));
}