A |= B means A is structure and B is a sentence "B IS TRUE IN A"
A |- B means A and B are sentences "SENTENCE A ENTAILS SENTENCE B" or "THERE IS A PROOF OF THEOREM B FROM AXIOMS A"
There is no such thing as "true but unprovable" because there is no way to compare truth in a structure to provable from axioms.
Structures aren't axioms.