Brand new install, no template, no file changes. PHP 8
Installing PayPal Pro throws the following error upon hitting the button to install it. Express installed fine.

[10-Jan-2023 10:07:41 UTC] PHP Fatal error: Uncaught Error: Undefined constant "MODULE_PAYMENT_PAYPALDP_DEBUGGING" in /home/devmel/public_html/xxx/includes/modules/payment/paypaldp.php:268
Stack trace:
#0 /home/xxx/public_html/xxx/xxx/modules.php(187): paypaldp->__construct()
#1 /home/xxx/public_html/xxx/xxx/index.php(11): require('/home/xxx/pu...')
#2 {main}
thrown in /home/xxx/public_html/xxx/includes/modules/payment/paypaldp.php on line 268

[10-Jan-2023 10:07:41 UTC] Request URI: /xxx/xxx/index.php?cmd=modules&set=payment&module=paypalwpp&action=edit, IP address: 000.000.000.000
--> PHP Fatal error: Uncaught Error: Undefined constant "MODULE_PAYMENT_PAYPALDP_DEBUGGING" in /home/xxx/public_html/xxx/includes/modules/payment/paypaldp.php:268
Stack trace:
#0 /home/xxx/public_html/xxx/xxx/modules.php(187): paypaldp->__construct()
#1 /home/xxx/public_html/xxx/xxx/index.php(11): require('/home/xxx/pu...')
#2 {main}
thrown in /home/xxx/public_html/xxx/includes/modules/payment/paypaldp.php on line 268.