MySQLi constant, MYSQLI_OPT_INT_AND_FLOAT_NATIVE, is undefined

I got this error day after installing on admin page:

MySQLi constant, MYSQLI_OPT_INT_AND_FLOAT_NATIVE, is undefined

My settings to fix:  In CPanel, for PHP 8.1, PHP extensions, disabled mysqli, enable mysqlnd, nd_mysqli, nd_pdo_mysql.  

PHP v7.4 by default i think has these settings and does not give error.

Correct, mysqlnd is the native driver optimized for mysql. Old libmysql returns numbers as strings, which throws some fatal errors in PHP 8.1 e.g. '4.99' + '9.99'. Therefore a warning is thrown if mysqlnd is missing.

nd_pdo_mysql is not needed by LiteCart.

I know this post is a little over a year old, but I have upgraded my PHP to 8.1 and have made all the correct selections based on the installer sheet info.  There are 3 exceptions however, In Modules, mod_deflate was not detected, mod_env was not detected and nd_pdo_mysql threw an error message that it wasn't allowed as it was a conflict. I am using Apache Version 2/ LiteSpeed.  Any ideas anyone?

Did you try searching the forums?
https://www.litecart.net/forums/search?query=MYSQLI_OPT_INT_AND_FLOAT_NATIVE

We don't use PDO. mysqli + nd_mysqli should be it for cPanel users.

I thank you for replying.  I don't have a clue why the error is still on the home page.  It is annoying.  Do you think i should uninstall and reinstall?  TY!

It's because you have enabled libmysql which was deprecated years ago in favour of mysqlnd (Native Driver).
You need to disable (lib)mysql and enable mysqlnd. cPanel users usually enable these two: mysqlnd + nd_mysqli.
Ask your web host how to do this. This does not recide in the LiteCart installation.
Did the other forum topics not help you at all?