Right now, there is no way to conditionally open the popup: either it always opens, or it does not open at all.
In your case, you can have it always opens the popup, and then choose manually which source website to use:
Get both the data:
{woocommerce={site: text; page=https://secure.goodnesslover.com/*; select=ifneeded; selector=:nth-child(2) > .address > :nth-child(2) > a}}
{shopify={site: text; page=https://admin.shopify.com/*; select=ifneeded; selector=p .Polaris-Button__Content_xd1mk}}
Choose data to use: {formmenu: default=woocommerce; shopify; name=choice}
{if: choice="shopify"}{address=shopify}{else}{address=woocommerce}{endif}
Address: {=address}
See also: Autopaste & {if} - #2 by scott