Here is a fix for the QR not showing
in file dbtech/twofactor/includes/GoogleAuthenticator.php find
replace with
in file dbtech/twofactor/includes/GoogleAuthenticator.php find
PHP:
return 'https://chart.googleapis.com/chart?chs='.$width.'x'.$height.'&chld='.$level.'|0&cht=qr&chl='.$urlencoded.'';
replace with
PHP:
return 'https://quickchart.io/qr?text='.$urlencoded.'&size='.$width.'&ecLevel=L&margin=1';