Segmently offers three paywall types, and the payment surface differs by type. Native Paywall: products attach as subscription rows you pick in the editor, and payment is collected with an embedded Stripe Payment Element right inside the funnel. Flexible-layout paywall: you assemble the screen from sections, attaching products through a product-catalog section and/or a custom-embed section - and a custom-embed section is always rendered inside an iframe at runtime. (The flexible-layout editor shows an iframe toggle on a custom-embed section, but that toggle is not honored at runtime for flexible-layout custom embeds: they always run inside an iframe regardless. So for wallet-sensitive paywalls, use a web-embed paywall with iframe rendering off, not a flexible-layout custom-embed.) Web-embed paywall: you bring your own HTML and attach products to your own buy controls, and a single toggle - 'Render in iframe (full isolation)' - governs the surface. Turn that toggle ON and the HTML runs in a legacy, fully isolated iframe; turn it OFF and the HTML runs in a Shadow DOM that shares the host window - this is the recommended, wallet-safe embedded surface and the one that includes the modern paid subscription flow. In short - the payment surface is set by which paywall type you chose plus, for a web-embed paywall, this iframe toggle - not by a single global on/off switch.