PMT returns the fixed payment that pays off a loan: =PMT(rate, nper, pv, [fv], [type]). Three details trip people up, and they're what Excel tests check.
Match the period. Lenders quote an annual rate, but most payments are monthly. Divide the rate by 12 and multiply the years by 12, so rate and nper describe the same period. Quarterly payments use 4.
Mind the sign. Excel follows the cash. The loan you receive is money in, so the payment comes back as a negative number. Type a minus before pv, as in -B3, and the payment shows as positive.
Point at cells. Keep the amount, rate and term in their own cells and reference them. Change an input and the payment updates. A number typed inside the formula breaks that link.
The optional arguments: fv is a balance left at the end (a balloon payment), and type 1 means payments at the start of each period, as with rent.