Product payment links use /link/<shortCode> (identity first, then pay). API sessions land on /pay/<sessionId>. Set NEXT_PUBLIC_WAKARI_API_URL and NEXT_PUBLIC_GOOGLE_CLIENT_ID.
/link/<shortCode>
/pay/<sessionId>
NEXT_PUBLIC_WAKARI_API_URL
NEXT_PUBLIC_GOOGLE_CLIENT_ID
Demo pay route: sample session