Printer, control method, and non-transitory computer-readable medium

A printer includes a head, a lamp, a first sensor, and a processor. The head is configured to eject photocurable ink onto the object to be printed supported by a platen. The lamp is configured to irradiate light onto the object to be printed on which the ink is ejected. The first sensor is provided inside the printer, and is configured to detect a temperature inside the printer. The processor causes the first sensor to acquire the temperature inside the printer. The processor acquires, based on the print data, a duty ratio indicating a printing ratio when ejecting the ink onto an ejection region of the object to be printed. The processor sets an illuminance of the light irradiated by the lamp, based on the temperature acquired by the first sensor and the acquired duty ratio.