When the plugin is activated, a One-Click button will appear on all the products of the shop, but only the users who have entered their shipping data or those who have at least purchased once will be able to see it unless you enable the option Activate for guest that you find in Settings > General options which allows redirecting guest customers to the Checkout page after clicking on the above-mentioned button.
If you want to restrict the plugin features only to users who have at least purchased once, you can enable the option Activate after the first order.
By default, the plugin adds a button on the product detail page, but you can also show it for every product on the shop page by checking the option Activate in shop page and users will be able to purchase them just with one click.
If you want to show a link instead of a button, enable the option Activate with link.
