So this is the code:
on place of head:
wait 4 seconds
set block at event-location to player's skull
I have also tried some other ways to do this like:
set block at event-location to skull of player
set block at event-location to ("%player%" parsed as offline player)'s skull
on place of head:
wait 4 seconds
set block at event-location to player's skull
I have also tried some other ways to do this like:
set block at event-location to skull of player
set block at event-location to ("%player%" parsed as offline player)'s skull