Using your HSA and FSA accounts to repay your FVYY balance are great ways to capitalize on tax advantages. You can add your HSA or FSA account through Plaid as a payment method in your FVYY account and then use them to cover any qualifying expenses. You cannot pay for veterinary expenses, non-qualifying health and wellness expenses with an HSA or FSA.
Please refer to the IRS website to determine whether transactions qualify as HSA/FSA expenses — and remember to always keep your receipts!