USlixury Organic Buckwheat Pillow for Sleeping with Extra Organic Pillowcase and Hulls, 20"X26" Buckwheat Hull Pillow, Adjustable Height and Firmness, Firm Neck Support for Side Sleepers, Cool, White

here you go: https://a.co/d/0aynDgp4

I have this one. I haven't tried any others so I can't compare it, but I like it a lot. Just know that they are very different from regular pillows. Very hard.

ETA: this is the pillow I have

I love that the pillow is heavy and you can add or remove filling to make it just the way you want it. Once if conforms to my head and neck, it stays put without going flat during the night. (I am a side sleeper and love to tuck it in just where I need it. I have also put it on my belly if I have a stomachache becasue it is a dense weighted pillow. I bought this one on Amazon. https://www.amazon.com/dp/B0BTV7KBMR?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_2&th=1