The app displays installment and invoice messaging widgets on product and cart pages, with configurable layout, colors, fonts, and info modals. Merchants set checkout display name, sort order, minimum and maximum cart total, allowed customer countries, allowed currencies, and company name requirements per Unzer payment method. Payment events from Unzer — captures, refunds, and cancellations — sync to Shopify orders. Each order links to its Unzer Insights transaction.