const github.com/refraction-networking/utls/dicttls.DHKEM_X25519_HKDF_SHA256

one use

	github.com/refraction-networking/utls/dicttls (current package)
		hpke_kem_identifiers.go#L15: 	DHKEM_X25519_HKDF_SHA256 uint16 = 0x0020 // RFC 7748