Photo 1 (the tailpiece and coupling nut) Video (under the kitchen sink - water dripping out of indicated gap)
I want to know if its an easy fix, or is this a replace all of the parts...not even sure where to order the parts.
Photo attached: Video link of leak: https://photos.app.goo.gl/CepX3CvxD1tnE6NWA
Update: I've added the missing gasket. It leaks a lot less (its down to a slight drip) Is the next missing part to replace: https://www.rona.ca/en/product/slip-joint-nut-abs-1-1-2-black-1236403