Apologies for the inconvenience.
Unfortunately, it is not possible to replace the "Add to Cart" button with an inquiry form in EasyStore. EasyStore is built as an eCommerce extension, not as a product catalog or inquiry-based system.
As an alternative, you may consider hiding the "Add to Cart" button and manually placing a static contact or inquiry form. However, please note that this would require custom implementation, and we do not provide support for such customizations.
Thank you for your understanding.