How to replace a helmet slot with a player skull

The Id tag is for the UUID of the player:

Id: UUID of owner. Optional. Used to update the other tags when the chunk loads or the holder logs in, in case the owner's name has changed.
_{from the wiki}

What you want is Name:

Name: Username of owner. If missing or empty, the head appears as a Steve head. Otherwise, used to store or retrieve the downloaded skin in the cache. Need not be a valid player name, but must not be all spaces.
_{also from the wiki}

So the command would be:

replaceitem entity @e[name=Intro] armor.head minecraft:player_head{display:{Name:"{\"text\":\"Open\"}"},SkullOwner:{Name:"Skraby_"}}