Fatal error: Uncaught Error: Call to a member function IPP() on null in /var/www/html/QuickBooks/IPP.php:1456 Stack trace: #0 /var/www/html/QuickBooks/IPP.php(334): QuickBooks_IPP->_request(NULL, 'ipp', 'https://workpla...', 'API_Authenticat...', '<?xml version="...') #1 /var/www/html/dev/dev_ids_salesreceipt.php(16): QuickBooks_IPP->authenticate('support@consoli...', '', 'bf8cp2mihs6vsdi...') #2 {main} thrown in /var/www/html/QuickBooks/IPP.php on line 1456