# Script tag (any storefront) (/yoursizer/integrations/script-tag) On Shopify, ikas, Ticimax, T-Soft, IdeaSoft and Faprika the widget is placed by the platform integration and you can skip this page. On any other storefront — WooCommerce and Magento 2 included, until their native integrations ship — you add one loader script tag. ## Copy the tag from the panel [#copy-the-tag-from-the-panel] Open **Widget → Install**. The tag already carries your store’s public key; paste it into the `` of every page. ```html title="every page — inside " ``` ## What the tag accepts [#what-the-tag-accepts] | Part | Required | What it does | | --- | --- | --- | | `YOUR_PUBLIC_KEY` | yes | Your widget’s public key, already filled in when you copy the tag from the merchant panel. It is public by design — it appears in your storefront source — and it identifies the store the recommendation, charts and analytics belong to. | | `?buttonTargetSelector=…` | no | A URL-encoded CSS selector added to the script address, for example `?buttonTargetSelector=%23size-slot`. The button is then placed inside that element. Without it, placement follows the layout set in the merchant panel. | | `yoursizer:cart-add` | no | A browser event fired on `window` when the shopper adds a size to the cart from the widget. `event.detail` carries `productId`, `variantId`, `selectedSize`, `gender`, `handledByPlatform` and `notice`. On a custom storefront `handledByPlatform` is `false` — listen for this event and add the item to your own cart. | ```html title="optional — connect add-to-cart on a custom storefront" ``` The script tag carries only your public key. Button text, design, measurement steps and placement are served with the widget configuration set on the Widget page of the merchant panel. Editing the tag does not change them — change them in the panel. The widget loads once per page. If a second YourSizer tag is present, it is skipped and the browser console names the key that won. On Shopify, a tag you pasted into the theme takes priority over the automatic app embed. ## How the widget finds the product [#how-the-widget-finds-the-product] It asks whether the current page address belongs to a product in your YourSizer catalogue, and only then shows the button. The address is normalised first — host lower-cased, query string, fragment and trailing slash removed — so tracking parameters do not matter. [Product identity →](/platform/developers#identity) ## What syncs and what is written back [#what-syncs-and-what-is-written-back]