I ordered a bunch of these from AliX :-
https://www.aliexpress.com/item/32955309866.html
They’re short enough as my Pegasus Astro Pocket PowerBox Advance sits under my GMK NUCBox, and furthermore I like the 90deg elbow bend for the DC2.1
And I also made my own from snipping the original USB-C cable that came with the computer and just soldered on an Oyaide DC2.1 plug. I really love these Oyaide plugs.
(Not certain why the pix is upside down!)