For a limited time, Lifepixel is offering 25% off any infrared or other camera conversions with coupon code Holiday2021 or $100 off on their already converted cameras (plenty of Nikon DSLR and mirrorless) with coupon code Camera2021. You can read about the different types of conversions here:
Hawaiian infrared time-lapse of haunting Mamane trees made with IR-converted Nikon D5200 camera