I found this one on Amazon in the US: https://www.amazon.com/BagMouth-pack-Keeps-Large-Trash/dp/B00BPBJF1S

Here is another: https://www.amazon.com/Bagrite-Trash-Holder-Gallon-Plastic/dp/B00UXPGK8I/ref=asc_df_B00UXPGK8I/?tag=hyprod-20&linkCode=df0&hvadid=311058902065&hvpos=1o1&hvnetw=g&hvrand=15215548424918710460&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9019429&hvtargid=pla-597035048394&psc=1

I don't think it has a specific name in English. I call it "a plastic or metal hoop for keeping a trash bag open."