Syntax
[purchase_link
id="ID| download ID - ID of the download"
price_id="false| price ID - ID of the variable price"
sku="| SKU - Stock Keeping Unit"
price="1| 0 - no"
direct="0| 1 - no"
text="| text - Add to cart or Buy now text"
style="button| plain - Button style"
color="dark-gray| white| gray| red| green| yellow| orange| dark-gray| inherit - Button color"
class="edd-submit| CSS classes - One or more custom CSS class names"
form_id="| form ID - Form ID"]