Alexa not find items configured with metadata

I’m try to configure items for alexa using metadata like descrived here

for example, i’ve this item:
Switch TVPower “TV” {alexa=“Switchable”}

I’ve installed Openhab Skill and tried to discover new items, but it doesn’t find it.

If i use:
Switch TVPower “TV” [Switchable]

no problem find it.

What i’m missing?

I trapped into this situation too. Docs state this:
Please note that the v3 skill is not available in the official Alexa store as of yet.