Problem during order a lab Test

Hello,
I have faced a problem in Open EMR 6.0.0 after creating a visit then click to Procedure Test to select a lab test I got this message

Fatal error: Uncaught TypeError: Unsupported operand types: int + string in C:\xampp\htdocs\openemr\interface\orders\find_order_popup.php:21 Stack trace: #0 {main} thrown in C:\xampp\htdocs\openemr\interface\orders\find_order_popup.php on line 21

I have opened find_order_popup.php on line 21 $labid = 0 + ($_GET[‘labid’] ?? null);

Thanks in advance