Case C-507/20: Order of the Court (Sixth Chamber) of 3 March 2021 (request for a preliminary ruling from the Pécsi Törvényszék — Hungary) — FGSZ Földgázszállító Zrt. v Nemzeti Adó- és Vámhivatal Fellebbviteli Igazgatósága (Reference for a preliminary ruling — Common system of value added tax (VAT) — Directive 2006/112/EC — Article 90 — Reduction of the taxable amount — Total or partial non-payment of the price — Debt which has become definitively irrecoverable — Limitation period regarding applications for a subsequent reduction in the taxable amount of VAT — Date on which time starts to run)