Magento 2 get custom customer attribute displayed value

I’m using the module Amasty’s customer Attributes to create custom customer attributes,
I like to get custom attribute displayed value but i got the option value.
I like to get the value in data-title attribute

I tried this

  if ($customAttribute = $customer->getCustomAttribute('custom_value')){
            $regrouper = $customAttribute->getValue();
            
            var_dump(regrouper);exit; //it returns 615 instead of 'Ok'
            
  }