Exercises @nevermined-io/ui-widgets-server (mints widget sessions) and
@nevermined-io/ui-widgets (mounts checkout + card delegation iframes)
against a local stack.
Pre-fill via ?env=&org=&secret= on the URL, or fill in below.
Sandbox uses test funds and a test chain; Live uses real funds.
UUID of the org that owns the widget key — find it in nevermined.app → Organisation settings.
Returned by POST /organisations/{id}/widget-keys at creation
(shown only once). Stays in this browser tab; forwarded server-to-server
exactly like an integrator's backend would.
Applies on the next widget mount. Out-of-range values are clamped by the SDK.