I was cleaning my air purifier today and saw exposed wires on the cord (photo attached). It's hard to see but it looks like this part of the cord has been flattened/run down and then popped open, but it has never been placed in between a door or in an area where it's stepped on. This has me thinking it might have been an issue since I've had it -- 2-2.5 years. Can anyone recommend the best way to replace this cord? Temporarily, I will cover it with electrical tape, but long term I'd want to replace it since I run it all the time.
FYI - I'm in the US.
Brand of Purifier: https://www.envionproducts.com/images/TPP230H_Mnl_3.15_R1.pdf