In shipping carrier class, there's a method to validate additional rules proccessAdditionalValidation, searching for that method in the code base will reveal processAdditionalValidation (less than 1 'c'). Then continue searching with that will lead collectCarrierRates
So in my opinion, there will be 2 approaches for this:
Extend the current Carrier, add ...
I haven't done something similar but as I checked the code right now, you can create an after Plugin for this method \Magento\Shipping\Model\CarrierFactory::createIfActive or also this method \Magento\Shipping\Model\Shipping::isShippingCarrierAvailable, there you can add your validation and return true or false for the shipping method you allow or not.
First create a Import Button in your Ui-component File
<?xml version="1.0" encoding="UTF-8"?>
<listing xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Ui/etc/ui_configuration.xsd&...