Purchase amount for an authorization.
This field contains the transaction amount to be authorized. The transaction amount is presented in US Dollars with a decimal point in the proper position. If sending a Debit transaction and the customer requests cash back, the TransactionAmount must include the total cost of the purchase, PLUS the DebitCashBack amount.
This must be formatted as a dollar amount with a real decimal point, excluding the dollar sign. For instance "12.00"