Magento 2 product custom attribute source_model outerset attribute not showing in product collection and not working in addAttributeToFilter()

Question

I am creating a custom product attribute in Magento 2 by custom module InstallData.php code following

    <?php
namespace Awa\Brand\\Setup;

use Magento\Eav\Setup\EavSetupFactory;
use Magento\Framework\Setup\InstallDataInterface;
use Magento\Framework\Setup\ModuleContextInterface;
use Magento\Framework\Setup\ModuleDataSetupInterface;

class InstallData implements InstallDataInterface
{
    /**
     * EAV setup factory
     *
     * @var \Magento\Eav\Setup\EavSetupFactory
     */
    private $eavSetupFactory;

    /**
     * Constructor
     *
     * @param EavSetupFactory $eavSetupFactory
     */
    public function __construct(
        EavSetupFactory $eavSetupFactory
    ) {
        $this->eavSetupFactory = $eavSetupFactory;
    }

    /**
     * {@inheritdoc}
     */
    public function install(
        ModuleDataSetupInterface $setup,
        ModuleContextInterface $context
    ) {
        $setup->startSetup();

        $eavSetup = $this->eavSetupFactory->create(['setup' => $setup]);


        $eavSetup->addAttribute(
            \Magento\Catalog\Model\Product::ENTITY,
            'awa_brand',
            [
                'type' => 'int', 
                'backend' => '',
                'frontend' => '',
                'label' => 'Attribute Select',
                'input' => 'select', 
                'class' => '',
                'source' => 'Awa\Brand\Model\Config\Source\Options',
                'global' => \Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface::SCOPE_STORE,
                'visible' => true,
                'required' => true,
                'user_defined' => false,
                'default' => '',
                'searchable' => false,
                'filterable' => false,
                'comparable' => false,
                'visible_on_front' => false,
                'used_in_product_listing' => true,
                'unique' => false,
                'apply_to' => ''
            ]
        );

        $setup->endSetup();
    }
}

and source Module is bellow

    <?php 
namespace Awa\Brand\Model\Config\Source;

class Options extends \Magento\Eav\Model\Entity\Attribute\Source\AbstractSource
{
    /**
     * to option array
     *
     * @return array
     */
     public function getAllOptions()
    {
        $_objManager = \Magento\Framework\App\ObjectManager::getInstance();
        $brandData = $_objManager->create('Awa\Brand\Model\Brand')->getCollection();
        $options = array();
        $options[] =[
                'value' => '',
                'label' => __('-- Please Select --')
            ];
        foreach($brandData as $_brand){
            $options[] =  [
                'value' => $_brand->getBrandId(),
                'label' => __($_brand->getTitle())
            ];
        }
        return $options;

    }

    public function toOptionArray()
    {
        $_objManager = \Magento\Framework\App\ObjectManager::getInstance();
        $brandData = $_objManager->create('Awa\Brand\Model\Brand')->getCollection();
        $options = array();
        $options[] =[
                'value' => '',
                'label' => __('-- Please Select --')
            ];
        foreach($brandData as $_brand){
            $options[] =  [
                'value' => $_brand->getBrandId(),
                'label' => __($_brand->getTitle())
            ];
        }
        return $options;

    }
}

This attribute created successfull

When I try to get product collection by this attribute its not working and this attribute not showing product collection

MY get product collection code following

<?php
$_product = $block->getProduct();

$objectManager = \Magento\Framework\App\ObjectManager::getInstance();
$productCollection = $objectManager->get('Magento\Catalog\Model\ResourceModel\Product\CollectionFactory');
$collection = $productCollection->create()
->addAttributeToFilter('awa_brand',array('eq' => $_product->getAwaBrand()))
->setPageSize(3);

foreach($collection as $product):
    echo '<pre/>'; print_r($product->getData());exit;
endforeach;

?>

Answer 1

Before addAttributeToFilter Function You Must Select All Attribute Using addAttributeToSelect Function

$collection = $productCollection->create()
->addAttributeToSelect('*')
->addAttributeToFilter('awa_brand',array('eq' => $_product->getAwaBrand()))
->setPageSize(3);

Answer 2

Use of objectmanager directly is not a good practice.
See the below code may help you:

protected $_productloader;

public function __construct(
     \Magento\Catalog\Model\ProductFactory $productloader
)
{
     $this->_productloader     = $productloader;
}

// function in which you want to access

function abc()
{
     $productId      = 10;
     $_product       = $this->_productloader->create()->load($productId);
     $awa_brand      = $_product->getData('awa_brand');
}