How to post extra options as URL parameters?

In general, WooCommerce lets you add products to your cart through URLs. Once the Allow posting extra options as url parameters option is selected, you can add the custom fields created using the plugin to your cart directly through the URL. 

For example:

http://yourwebsite.com/?add-to-cart=10&field_1=field_1_value&field_2=field_2_value&thwepo_product_fields=field_1,field_2 

Here, the product gets added to the cart along with the custom-created fields field_1 and field_2.