Sorry man, I must have completely missed this, but I took a video tonight. I forgot my bands and tried to use the cable machine. It didn’t work because there was only one ankle strap. It won’t let me upload it, but here’s some stills
I usually just loop the band around the GHR, but you could just go around the base of the box. Because I didn’t have my bands the stretch under wasn’t as good or drastic as it normally is. I went higher rep and just made sure to really tuck underneath. Hope this helps man.
PSA: I’ve never used an actual RH, but I watched videos and tried to emulate it as well as I could in a commercial setting. Using this set up has helped me a ton in low back health, strength and overall mobility.