Can /give or /clear only piglin skull

Soory, I'm not english so some grammars mistake can arriver...

Problem: I have tried made a shop on my server with command block and discover we can't /clear or /give only piglin skull. Normaly, inch skull have a number to specified him, but not piglin skull.

Exemple: the command "/clear @p skull any number between 0 and 6{} 1" clear only one skull in your inventory depending on the number you placed (1 for skeleton skull, 2 for wither skeleton skull, 3 for zombie skull, ...), but piglin don't have any number. BUT piglin skull is really a skull cause when command "/clear @p skull" is execute, piglin skull get clear with all the other skull.

And its the same problem with /give where piglin skull is just not givable.

 

command: "/clear @p skull 7 1"

Suppose to happen: clear a piglin skull from the inventory of the closer player

What happening: skull 7 is not a valid item

 

Thanks correct this promblem.