Update form give access for specific users only - M2

Question

How to restrict update form for few users using ACL ?

Answer 1

Create empty M2 module and then:

Your etc/admin/di.xml:

<?xml version="1.0" ?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <preference for="Magento\CustomerBalance\Block\Adminhtml\Customer\Edit\Tab\Customerbalance\Form" type="NameSpace\YourModule\Block\Adminhtml\Customer\Edit\Tab\Customerbalance\Form" />

</config>

And now, your class: NameSpace\YourModule\Block\Adminhtml\Customer\Edit\Tab\Customerbalance\Form.php

<?php

namespace NameSpace\YourModule\Block\Adminhtml\Customer\Edit\Tab\Customerbalance;

use Magento\Customer\Model\Customer;
use Magento\Framework\AuthorizationInterface;

class Form extends \Magento\CustomerBalance\Block\Adminhtml\Customer\Edit\Tab\Customerbalance\Form
{

    protected $authorization;

    public function __construct(
        \Magento\Backend\Block\Template\Context $context,
        \Magento\Framework\Registry $registry,
        \Magento\Framework\Data\FormFactory $formFactory,
        \Magento\Customer\Model\CustomerFactory $customerFactory,
        \Magento\Store\Model\System\Store $systemStore,
        AuthorizationInterface $authorization,
        array $data = []
    ) {
        $this->authorization = $authorization;
        parent::__construct($context, $registry, $formFactory, $customerFactory, $systemStore, $data);
    }
    
    protected function _prepareForm()
    {
        if (!$this->_isAllowed()) {
            return $this;
        }
        
        return parent::_prepareForm();
    }

    /**
     * Determines whether current user is allowed to access Action
     *
     * @return bool
     */
    protected function _isAllowed()
    {
        return $this->authorization->isAllowed('NameSpace_YourModule::your_acl');
    }
}

And, now add acl:

<?xml version="1.0" ?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Acl/etc/acl.xsd">
    <acl>
        <resources>
            <resource id="Magento_Backend::admin">
                <resource id="NameSpace_YourModule::your_acl" sortOrder="5" title="YourAcl" />
            </resource>
        </resources>
    </acl>
</config>

Now if you go to system > user roles and then add new role, you should see your added acl in there. The form will appear only if you tick this.

Haven't tested it, this should work.