Where can I find a replacement diagnostic port cover?

Hi guys,

So basically on every Apple watch, if you take off the band for the bottom part of the watch, you can see the diagnostic port. Me being the idiot I took off the port cover and lost it.

I tried looking all over online to see if they sell replacement port covers to no avail.

Does anyone know where I can buy a replacement port cover for the Apple watch, I think they are all the same size but just for reference I have a 40mm series 4 watch.

This video will give you an understanding on what I am talking about: https://www.youtube.com/watch?v=qk0w3o1x...

Thanks!