If you can't find it, it's very likely not supported. While AMF support HEVC encoding, its likely support the standard 8 bit, not the 10 bit profile.
It is hard to tell as AMD is quite vague on the encoder/decoder supported per model, unlike Nvidia. At least not within my 5 minute search.
Honestly, I would advice you get a second hand 1660S if you need hardware acceleration absolutely, like Plex/Jellyfin transcode. Otherwise, I will stick to CPU as that give better overall quality at the same size.