NOWPayments checkout is not enabled — add API credentials
nowpayments-checkout assert failed. Product: add API credentials in Admin → Settings → Payment and turn on NOWPayments checkout.
Why this happens
Enable flag false or required API credentials missing before creating an invoice.
Diagnose and fix
1. Paste API key; enable checkout; save.
2. Configure IPN secret so paid invoices can credit the account (Invalid IPN signature if wrong).
3. Retry; if enabled but no URL, see NOWPayments did not return an invoice URL.
4. See NOWPayments for dashboard field locations.