Creating product attribute programmatically in Magento 2.3.5

Question

Ive tried to add 2 product attributes in Magento 2.3.5 programatically using install data. The attributes aren't being created and after some searching i found out that > 2.3.3 install and upgrade data where phased out for a declarative approach. Does anyone have any examples on how to do this outside of installdata/upgradedata? Here is what i was trying to add:

<?php
 
namespace XX\Pricing\Setup;
 
use Magento\Eav\Setup\EavSetup;
use Magento\Eav\Setup\EavSetupFactory;
use Magento\Framework\Setup\InstallDataInterface;
use Magento\Framework\Setup\ModuleContextInterface;
use Magento\Framework\Setup\ModuleDataSetupInterface;
 
class InstallData implements InstallDataInterface 
{
    private $eavSetupFactory;
 
    public function __construct(EavSetupFactory $eavSetupFactory) 
    {
        $this->eavSetupFactory = $eavSetupFactory;
    }
 
    public function install(ModuleDataSetupInterface $setup, ModuleContextInterface $context) 
    {
        $eavSetup = $this->eavSetupFactory->create(['setup' => $setup]);
 
        $eavSetup->removeAttribute(\Magento\Catalog\Model\Product::ENTITY, 'product_price_tier');
        $eavSetup->addAttribute(\Magento\Catalog\Model\Product::ENTITY, 'product_price_tier', [
            'group' => 'Product Price Tier',
            'type' => 'int',
            'sort_order' => 200,
            'backend' => '',
            'frontend' => '',
            'label' => 'Custom Yes/No',
            'input' => 'boolean',
            'class' => '',
            'source' => 'Magento\Eav\Model\Entity\Attribute\Source\Boolean',
            'global' => \Magento\Catalog\Model\ResourceModel\Eav\Attribute::SCOPE_GLOBAL,
            'visible' => true,
            'required' => false,
            'user_defined' => false,
            'default' => '',
            'searchable' => false,
            'filterable' => false,
            'comparable' => false,
            'visible_on_front' => false,
            'used_in_product_listing' => true,
            'unique' => false,
            'apply_to' => ''
        ]);
 
        $eavSetup->removeAttribute(\Magento\Catalog\Model\Product::ENTITY, 'product_price_family');
        $eavSetup->addAttribute(\Magento\Catalog\Model\Product::ENTITY, 'product_price_family', [
            'group' => 'Product Details',
            'type' => 'varchar',
            'backend' => '',
            'frontend' => '',
            'sort_order' => 220,
            'label' => 'Product Price Family',
            'input' => 'text',
            'class' => '',
            'global' => \Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface::SCOPE_GLOBAL,
            'visible' => true,
            'required' => false,
            'user_defined' => false,
            'default' => '',
            'searchable' => false,
            'filterable' => false,
            'comparable' => false,
            'unique' => false,
            'visible_on_front' => false,
            'used_in_product_listing' => true,
            'apply_to' => ''
        ]);
    }
}

Answer 1

You can create product attribute by using Magento default feature instead of going with programmatically.

Answer 2

Try this.

<?php

namespace Foo\Bar\Setup\Patch\Data;

use Magento\Catalog\Model\Product;
use Magento\Eav\Setup\EavSetupFactory;
use Magento\Framework\Setup\ModuleDataSetupInterface;
use Magento\Framework\Setup\Patch\DataPatchInterface;

class AddProductAttributeExample implements DataPatchInterface
{
    /**
     * @var ModuleDataSetupInterface
     */
    protected $moduleDataSetup;

    /**
     * @var EavSetupFactory
     */
    protected $eavSetupFactory;

    /**
     * AddProductAttributeExample constructor.
     *
     * @param ModuleDataSetupInterface $moduleDataSetup
     * @param EavSetupFactory $eavSetupFactory
     */
    public function __construct(
        ModuleDataSetupInterface $moduleDataSetup,
        EavSetupFactory $eavSetupFactory
    ) {
        $this->moduleDataSetup = $moduleDataSetup;
        $this->eavSetupFactory = $eavSetupFactory;
    }

    /**
     * @inheritDoc
     */
    public static function getDependencies()
    {
        return [];
    }

    /**
     * @inheritDoc
     */
    public function getAliases()
    {
        return [];
    }

    /**
     * @inheritDoc
     */
    public function apply()
    {
        $this->moduleDataSetup->startSetup();
        $eavSetup = $this->eavSetupFactory->create(['setup' => $this->moduleDataSetup]);

        $eavSetup->addAttribute(
            Product::ENTITY,
            'attribute_code',
            [
                // attribute params
            ]
        );

        $this->moduleDataSetup->endSetup();
        return $this;
    }
}