Remove from a Shopify store or WordPress site

Puts the Meta pixel on a connected Shopify store's storefront and checkout through Zernio's Shopify web pixel (a Shopify app pixel, no theme edits). The store then sends PageView, ViewContent, AddToCart, Search, InitiateCheckout, AddPaymentInfo and Purchase (with value, currency, content_ids and contents) to the pixel, each with an event id. Purchase uses `shopify_order_{orderId}` as its event id, so a Conversions API Purchase you send for the same order with that `eventId` is deduplicated by Meta. Idempotent: a store runs one Zernio pixel, so calling it again updates the install and installing a different tag replaces the previous one (reported in `replacedTagId`). Events respect the store's customer privacy settings (marketing consent). `accountId` is the Meta ads account that owns the pixel (`tagId`); `storeAccountId` is the Shopify account. Stores connected before pixel support must re-approve the Zernio app: the call then answers 409 `reconnect_required` with `details.authUrl` to send the merchant to (the Shopify account id stays the same). Meta only (platform `metaads`); other platforms return 405. **WordPress** (`storeAccountId` is a connected WordPress.com or self-hosted site): Zernio adds a Custom HTML widget with the Meta pixel base code (fbevents.js, `init`, `PageView`) to a widget area of the active theme (a footer area when there is one, else the first active area; pass `sidebarId` to choose), then reads the widget back to confirm WordPress kept the `<script>` tag. The widget carries a Zernio marker, so the call is idempotent per pixel: repeating it updates or moves the same widget, and pixel code the site owner pasted by hand is never touched. Several pixels can run side by side (one widget each). When the site cannot run the pixel, nothing is left behind and the call answers 422 `tracking_tag_install_blocked` with `details.reason`: - `insufficient_permissions`: the connected user lacks `edit_theme_options` (needs Administrator). - `scripts_stripped`: WordPress removed the script (the user lacks `unfiltered_html`, e.g. a multisite admin who is not a Super Admin, or `DISALLOW_UNFILTERED_HTML` is set). - `wordpress_com_plan`: a WordPress.com plan that strips scripts (plans without plugins). - `no_widget_areas`: the theme has no widget areas (block themes such as Twenty Twenty-Five). - `widgets_api_unavailable`: no widgets REST API (WordPress older than 5.8, or disabled). The `error` message names the manual alternative (Meta's official WordPress plugin). With `verifyHomepage` (default true) the homepage is fetched afterwards and `homepageCheck` says whether the pixel is visible; `not_found` can be a stale page cache, the widget read-back is authoritative.