On the plastic insert, I made a smaller hole that serves as the nozzle, smaller than the original size. It may be sufficient for some users, but it is primarily intended as a guide for possible further enlargement using a knife or a file. It is smaller because washer pumps of different ages may already be worn, so everyone can adjust the nozzle size according to their own needs.

I printed it using the following configuration: Prusa i3 MK3S, PLA, 100% infill, 0.15 mm layer height, and brim enabled.