Assuming you have the same radio version as the one in this listing, that's just the regular Baofeng 2-way programming cable that u/jack_shid linked in the Google search. Just be careful that when buying the cable you get the one with the small pins (see Amazon listing) and not the larger one that uses the inputs for the mic/speaker (Kenwood style cable). I probably missed it but I didn't even see a picture of a cable in the blog link you included. Unless you were meaning the output testing device he was using.

https://www.amazon.com/Baofeng-Waterproof-Repeater-Rechargeable-Programming/dp/B09Q5XLF1C

Edit: here's the cable it should be. Hopefully someone else can chime in to confirm as I don't have the radio myself and am going off of the listings - https://www.amazon.com/Original-Baofeng-Waterproof-Programming-Software/dp/B06XHSPJZ4/ref=mp_s_a_1_10?crid=5UTSA02GKAWT&keywords=baofeng+cable+programming&qid=1671626905&sprefix=Baofeng+cable%2Caps%2C190&sr=8-10