Magento 2.3: How I can create a text swatch attribute programatically?

In my InstallData class I have the following code, it perfectly creates the attribute for me but this creates it as Dropdown and I need it to be Swatch Text.

What option am I missing?

$productTypes = [
        \Magento\Catalog\Model\Product\Type::TYPE_SIMPLE,
        \Magento\Catalog\Model\Product\Type::TYPE_VIRTUAL,
        \Magento\Downloadable\Model\Product\Type::TYPE_DOWNLOADABLE,
        \Magento\Catalog\Model\Product\Type::TYPE_BUNDLE,
    ];
    $productTypes = join(',', $productTypes);

    $eavSetup->addAttribute(
        \Magento\Catalog\Model\Product::ENTITY,
        'web_volumen',
        [
            'type' => 'int',
            'group' => 'Module',
            'backend' => 'Magento\Eav\Model\Entity\Attribute\Backend\ArrayBackend',
            'source' => 'Magento\Eav\Model\Entity\Attribute\Source\Table',
            'label' => 'VOLUMEN',
            'input' => 'select',
            'class' => '',
            'global' => \Magento\Eav\Model\Entity\Attribute\ScopedAttributeInterface::SCOPE_GLOBAL,
            'visible' => true,
            'required' => false,
            'user_defined' => true,
            'default' => '',
            'searchable' => true,
            'filterable' => true,
            'comparable' => false,
            'visible_on_front' => true,
            'used_in_product_listing' => true,
            'apply_to' => $productTypes,
        ]
    );