.unpriceFormat is not a function

[doubleprincez]

When used in function, I get the error " specialBonusAmount.unpriceFormat is not a function", when i tried to get the price from the input field and also return it back to the display div

        $("#specialBonusAmount").priceFormat({
            prefix: '₦',
            centsSeparator: '.',
            thousandsSeparator: ','
        });

  function addSpecialBonus() {
            let specialBonusAmount =  $("#specialBonusAmount");
             specialBonus = specialBonusAmount.unpriceFormat();
            console.log("special "+specialBonus);
            let amountDisplay = $("#amountDisplay");
            amountDisplay.text(specialBonus).priceFormat();
}

please what is the right way to carry out the above function?