By using GraphQL, You can get data of logged in customers.

Magento 2 can directly call api to get data by resolver.

Module name : Magemonkeys::Custom

create file schema.graphqls in etc folder in that module

type Query
{
    getCustomerData: Response 
    @resolver(class:"Magemonkeys\Custom\Model\Resolver\Getdataforcustomer")
}

type Response
{
    customer_id: String
    customer_name: String
}

Create Getdataforcustomer.php in Model/Resolver Folder in that module

namespace MagemonkeysCustomModelResolver;

use MagentoFrameworkGraphQlQueryResolverInterface;
use MagentoFrameworkGraphQlConfigElementField;
use MagentoFrameworkGraphQlSchemaTypeResolveInfo;
use MagentoFrameworkGraphQlExceptionGraphQlNoSuchEntityException;
use MagentoFrameworkGraphQlExceptionGraphQlAuthorizationException;
use MagentoCustomerGraphQlModelCustomerGetCustomer;

class Getdataforcustomer implements ResolverInterface
{
   private $getdataforCustomer;
     
   public function __construct(GetCustomer $getdataforCustomer)
   {
      $this->getCustomer = $getdataforCustomer;
   }
   public function resolve(Field $field, $context, ResolveInfo $info, array $value = null, array $args = null)
   {
      try
      {
         if (false === $context->getExtensionAttributes()->getIsCustomer())
         {
            throw new GraphQlAuthorizationException(__('The current customer not getting'));
         }
         $customerdata = $this->getCustomer->execute($context);
         $customername = $customerdata->getFirstName()." ".$customerdata->getLastName();
         $result = ['customer_id' => $customer->getId(),
                    'customer_name' => $customername
                   ];   
         return $result;
      }
      catch(Exception $exception)
      {
          throw new GraphQlNoSuchEntityException(__($exception->getMessage()));
      }
   }
}

After that run command to call api url

That’s it.