The payment is the standard monthly amortization of the amount, rate, and term you enter. Interest is the payment times the number of months, minus the amount borrowed. An origination fee is part of the cost only when the form asks for it or you have added it to the amount.
Borrowing $10,000 at 12% for 36 months produces a fixed payment that covers interest and principal. The total of the 36 payments is more than $10,000 by the interest. A 0% rate makes the payment the amount divided by the months.
A late fee, a variable rate, and credit insurance are not added. The APR a lender advertises may already include a fee that this payment ignores unless you enter it.