Done with errors on the page

Notice: Trying to access array offset on value of type null in /home/stemmjobs/stemmjobs.com/system/user-scripts/payment/products.php on line 69
Notice: Trying to access array offset on value of type null in /home/stemmjobs/stemmjobs.com/system/user-scripts/payment/products.php on line 255
Notice: Trying to access array offset on value of type null in /home/stemmjobs/stemmjobs.com/system/user-scripts/payment/products.php on line 270