VScode - undefined 'getVar' method in version 4.1.2

This is because of the incomplete interface dependence CI4 has. It is typehinted to the interfaces but those interfaces clearly do not have the methods being called as those methods are defined in the implementing classes. You can safely ignore those intelephense errors for now.

For the Kint error, the CodeIgniter class has a custom autoloader for Kint, which class alias `Kint\Kint` as only `Kint`. Since intelephense indexes based on the vendor/autoload.php, it doesn't understand the `Kint` alias. Ignore for now, please.