WP BackOffice

Link directly to a specific WooCommerce product variation using get variables – yoursite.com/your-single-product/?size=small&color=blue. This is useful if you want to send an email to customers and send them directly to a specific variation without them having to enter it in themselves.
Usage/Examples:
Attach: ‘?[variation_name]=[variation_value]‘ to the end of your product link to have the variations automatically appear on the user’s screen.
<ul>
<li>mysite.com/product/happy-ninja/?color=blue</li>
<li>mysite.com/product/happy-ninja/?color=blue&size=small (additional variations should be separated by ‘&’)</li>
<li>mysite.com/product/happy-ninja/?color=blue+green (where the variation value is “Blue Green” with the space replaced by a ‘+’)</li>
</ul>
Features:
<ul>
<li>No configuration needed, just install and start using</li>
<li>Supports an infinite number of variations</li>
<li>Fails gracefully, if the option or value doesn’t exist, the default value will appear instead</li>
<li>Default selected variations work if no product is specified in url</li>
<li>100% case insensitive</li>
<li>Works with any variation settings you have ie. custom images, prices etc.</li>
</ul>
<a href="http://wpbackoffice.com/plugins/woocommerce-direct-variation-link/" rel="nofollow ugc">Plugin’s Official Documentation and Support Page</a>

WooCommerce Direct Variation Link

Link directly to a specific WooCommerce product variation using get variables (yoursite.com/your-single-product?size=small&color=blue).

damasovelazquez

Generate custom links to add products to the WooCommerce cart and redirect to cart or checkout based on your configuration.
This plugin allows you to create direct “Add to Cart” links for your WooCommerce products with the following features:
<ul>
<li>Generate direct links to add products to cart</li>
<li>Choose redirect destination: cart page or checkout page</li>
<li>Copy links directly from the product edit screen</li>
<li>Configure default redirect behavior in WooCommerce settings</li>
<li>Secure links with nonce verification</li>
<li>Simple and lightweight implementation</li>
</ul>
Perfect for marketing campaigns, email newsletters, social media posts, or any situation where you want to provide a direct purchase link.

Add to Cart links generator for WooCommerce

Generate quick links to add products to the cart and redirect to cart or checkout using custom parameters.

WooCommerce Direct Variation Link vs Add to Cart links generator for WooCommerce