Deprecated function: round(): Passing null to parameter #1 ($num) of type int|float is deprecated

Please give the steps to reproduce this issue .

1. Use PHP 8.1 or newer,
2. add this to settings.php to show each PHP error on page and clear caches:
$config['system.logging']['error_level'] = 'verbose';
3. set up the module as written in documentation
4. add points for a user to use
5. add something to the cart and start checkout
6. try to use your points for the order
7. that error should be shown and logged what I mentioned. Also if core dblog module is enabled, then it should also be at /admin/reports/dblog

I have fixed this issue Deprecated function: round(): Passing null to parameter #1 ($num) of type int|float is deprecated please review above attached patch

Changes are added now in 3.0.x branch, Thanks for the patch @Mohd Sahzad.

Automatically closed - issue fixed for 2 weeks with no activity.