Lemon Squeezy checkout is not enabled — add API credentials, store ID, and variant ID
lemon-squeezy-checkout assert failed. Product: add API credentials, store ID, and variant ID in Admin → Settings → Payment and turn on Lemon Squeezy checkout.
Why this happens
Enable flag false or required fields missing before creating a checkout session.
Diagnose and fix
1. Fill all three fields; enable checkout; save.
2. Match variant ID to the product members should buy.
3. Retry; if enabled but no URL, see Lemon Squeezy did not return a checkout URL.
4. See Lemon Squeezy for field locations in the Lemon dashboard.