https://wyred4sound.com/products/hdmi-pcocc-premium

That's what I use.  I haven't tried any standard hdmi cables. 

The I2S over HDMI format is frustrating because there really isn't a set standard for the pinouts that is adopted and used by every brand. Instead we get a bunch of different configurations to the point where you are only guaranteed compatibility when using the same brand for transport and DAC. 

Sometimes they don't work at all due to different formats. Other times I've experienced playback that sounded weird, or out of phase, or worked for PCM but not DSD. It all comes down to how each brand does their configuration. If I remember correctly I think Denafrips uses the same style as PS Audio and several other brands for I2S. So there should be at least some options when mixing brands. I don't know about LAIV yet though.

I would just try a regular HDMI cable that you probably already have laying around somewhere. See if you get sound at first, then listen for any distortion or choppy sound, that sort of thing. Then make sure you can do hi-res and DSD without issues. If all that seems to work then you've passed the test, and you might consider trying a nicer HDMI cable.

Obviously HDMI cable will work, I'd suggest using I2S cable for long term, this especially  if considering higher cost options. In consideration of costly material such as silver why pay for the unneeded runs in HDMI cables, 19 pins vs 8 pins/runs. As for sound quality, haven't directly compared HDMI to I2S. If more costly cables considered I'd suggest Tubulus, I use the Ximius.

You want to use the shortest cable possible. Typical hdmi cables might be fairly long.

I'm using a 0.5 meter Wyred for Sound cable that I linked above. It is supposedly designed for I2S and not simply a hdmi cable.  I thought the price was reasonable compared to a lot of other cables. 

Any HDMI cable will work, but optimally you want the cable to be a foot or less.  I use this and the sound is so good I’m not itching to upgrade, and as the 1 foot length is only 8 bucks it might be a good option just to test it out without risking $$$.

https://www.monoprice.com/product?p_id=24187

If you wanna buy something better I think the Wyred 4 Sound cable mentioned by @sls883 mentioned looks very interesting, and the DH Labs HDMI 2.1 is probably good as well but minimum length is 1.6 feet.  Frankly I think any are good enough to tell you if the connection itself is superior.  Hope this helps. 

@soix I did use the Monoprice cable and a DH Labs cable, but not with my current dac. They seemed to work fine. I used a short cable in both cases.

I had forgotten about the short Monoprice cable until you mentioned it. I was thinking of the many longer hdmi cables that I use for computer monitors, etc. 

I’ve never tried swapping them out and doing an a/b comparison.

SUPREME HDMI MKII Digital Video Cable HDMI 2.0 Bandwidth 29 Gbps and Audio I²S

https://www.ricable.com/en/prodotto/supreme-hdmi-cavo-video-digitale-hdmi-2-0-bandwidth-29-gbps-e-audio-i2s/?swcfpc=1

I tried almost a dozen different cable manufacturers to no avail in trying to get a custom made I2S cable with different "pinouts" at each end. Most of the hardware manufacturers do supply a diagram of the pin configurations which use a male HDMI style connector. Some of the newer gear has user configurable options for the pin-out, but it is worth verifying before you buy the gear that the I2S connection on both ends will match. I finally got what I needed by buying a DDC from the same company as my DAC (Gustard) and it can accept a standard HDMI configuration for I2S. I had temporarily used a 6" HDMI cable which was probably HDMI 2.0 and eventually bought the DH Labs .5 meter for connection between the DDC and DAC. That I2S connection, and the additional isolation provided by the DDC give a low cost digital front end a real qualitative improvement running through a top tier analog system. I was never a digital fan, and I am actually enjoying this- using the set up to play files from an SSD using the Shanling ET3 as the player. It is a fraction of the cost of my analog front end and I'm quite impressed with the SQ, especially given how little money was spent on the digital front end. 

.5M or less for cable, this even more important if one is syncing to DDC clock vs dac internal clock.

DH Labs Silver Sonic .5M cable is nice. I compared this to a much more expensive cable of the same length and at first thought I heard some difference, but I think I learned something about confirmation bias that day.  I did some later A/B comparisons and could detect no noticeable difference between the two cables.