Configuring a Gravity Forms Product
First, create your form in Gravity Forms. You can use the Pricing Field options to add variations to your product to manipulate the price the customer pays and what they are getting for the price. For more information on how to use this add-on, please see the Gravity Forms Product Add-ons plugin documentation.
Add Form To A WooCommerce Product
Create a new product, or edit an existing product in WooCommerce.
In the product data box, there will be a Gravity Forms tab. Click there and choose the form you just created. There will be other options for the display of the form on the product page, which you can use if needed to control how this form is displayed to your customers.
Configure Quick Checkout
Click the Quick Checkout tab in the Product Data box. You can use this section to customize how Quick Checkout will behave for this particular product. Additionally, you can leave the product to use the Global Settings if you have them enabled in the WooCommerce > Settings > Quick Checkout tab.