Disable First & Last name in customer account and pass the existing value to POST

I want to prevent customers from changing their first and last name once they’re registered but I want to allow them to change the password in customer account.

I added disabled = "disabled" to first and last name input field:

app/design/frontend/Vendor/ctr/Magento_Customer/templates/widget/name.phtml

<div class="field field-name-firstname required">
            <label class="label" for="<?= $block->escapeHtmlAttr($block->getFieldId('firstname')) ?>"><span><?= $block->escapeHtml($block->getStoreLabel('firstname')) ?></span></label>
            <div class="control">
                <input type="text" id="<?= $block->escapeHtmlAttr($block->getFieldId('firstname')) ?>"
                       name="<?= $block->escapeHtmlAttr($block->getFieldName('firstname')) ?>"
                       value="<?= $block->escapeHtmlAttr($block->getObject()->getFirstname()) ?>"
                       disabled="disabled"
                       title="<?= $block->escapeHtmlAttr($block->getStoreLabel('firstname')) ?>"
                       class="input-text <?= $block->escapeHtmlAttr($block->getAttributeValidationClass('firstname')) ?>" <?php if ($block->getAttributeValidationClass('firstname') == 'required-entry') echo ' data-validate="{required:true}"' ?>>
            </div>
        </div>

Now, my input fields are grayed out but when I change my password I get

“First name is required. Last name is required”

I created a before plugin for vendor/magento/module-customer/Controller/Account/EditPost.php so I can inject EXISTING first and last name before POST executes so I can prevent this error from appearing and make sure customer’s existing first and last name are not changed.

app/code/Vendor/Customer/etc/frontend/di.xml

<type name="MagentoCustomerControllerAccountEditPost">
     <plugin name="disableCustomerFields" type="VendorCustomerPluginControllerAccountDisableCustomerPost" />
</type>

PLUGIN: app/code/Vendor/Customer/Plugin/Controller/Account/DisableCustomerPost.php

<?php

namespace VendorCustomerPluginControllerAccount;

use MagentoCustomerApiCustomerRepositoryInterface;
use MagentoCustomerApiDataCustomerInterface;
use MagentoCustomerControllerAccountEditPost;
use MagentoCustomerModelCustomerExtractor;
use MagentoCustomerModelSession;
use MagentoFrameworkAppActionAbstractAction;
use MagentoCustomerModelCustomerMapper;
use MagentoFrameworkAppRequestInterface;

class DisableCustomerPost
{
    /**
     * @var CustomerRepositoryInterface
     */
    protected $customerRepository;

    /**
     * @var Session
     */
    protected $session;

    /**
     * @var Mapper
     */
    protected $extensibleDataObjectConverter;

    /**
     * @var CustomerExtractor
     */
    protected $customerExtractor;

    /**
     * Form code for data extractor
     */
    const FORM_DATA_EXTRACTOR_CODE = 'customer_account_edit';

    /**
     * @var EditPost
     */
    protected $editPost;

    /**
     * EditPost constructor.
     *
     * @param CustomerRepositoryInterface $customerRepository ,
     * @param Session $customerSession ,
     * @param EditPost $editPost
     */
    public function __construct(
        CustomerRepositoryInterface $customerRepository,
        Session                     $customerSession,
        Mapper                      $extensibleDataObjectConverter,
        CustomerExtractor           $customerExtractor,
        EditPost                    $editPost
    )
    {
        $this->customerRepository = $customerRepository;
        $this->session = $customerSession;
        $this->extensibleDataObjectConverter = $extensibleDataObjectConverter;
        $this->customerExtractor = $customerExtractor;
        $this->editPost = $editPost;
    }

    /**
     * Get customer data object
     *
     * @param int $customerId
     *
     * @return CustomerInterface
     */
    private function getCustomerDataObject($customerId): CustomerInterface
    {
        return $this->customerRepository->getById($customerId);
    }

    /**
     * Populate customer data with existing full name
     * @param RequestInterface $request
     * @param CustomerInterface $currentCustomerData
     * @return array
     */
    private function addExistingFirstandLastname(
        RequestInterface $request,
        CustomerInterface $currentCustomerData
    ): array
    {
        /** @var Mapper $extensibleDataObjectConverter */
        $attributeValues = $this->extensibleDataObjectConverter->toFlatArray($currentCustomerData);
        $customerDto = $this->customerExtractor->extract(
            self::FORM_DATA_EXTRACTOR_CODE,
            $request,
            $attributeValues
        );
        $customerDto->setId($currentCustomerData->getId());
        if (!$customerDto->getFirstname()) {
            $customerDto->setFirstname($currentCustomerData->getFirstname());
        }
        if (!$customerDto->getLastname()) {
            $customerDto->setLastname($currentCustomerData->getLastname());
        }
        return $customerDto;
    }

    /**
     * @param MagentoCustomerControllerAccountEditPost $subject
     * @return mixed
     */
    public function beforeExecute(EditPost $subject)
    {
        $post = $subject->getRequest()->getPostValue();
//            /** @var RequestInterface $request */
            $currentCustomerDataObject = $this->getCustomerDataObject($this->session->getCustomerId());
            $customerCandidateDataObject = $this->addExistingFirstandLastname($post, $currentCustomerDataObject);
            return $this->session->setCustomerFormData($customerCandidateDataObject);
    }
}

but I’m getting different errors such as:

Fatal error: Uncaught TypeError: Argument 1 passed to VendorCustomerPluginControllerAccountDisableCustomerPost::addExistingFirstandLastname() must implement interface MagentoFrameworkAppRequestInterface, array given, called in /app/app/code/Vendor/Customer/Plugin/Controller/Account/DisableCustomerPost.php on line 117 and defined in /app/app/code/Vendor/Customer/Plugin/Controller/Account/DisableCustomerPost.php:86 Stack trace: #0

I know my function for getting current customer name and setting current customer name is not written properly and then sending that data to POST controller but I don’t have an idea of how to make it work.