You are probably copying example code from the wrong version of minecraft, things like this can change between versions.
MobRepellentBlockEntity::new passes a reference to your constuctor, which must match the signature of BlockEntityType.BlockEntitySupplier - the parameter type used by of()
In 1.19 that is (BlockPos, BlockState) - see the create() method of this functional interface.
Your constructor has signature (BlockEntityType, BlockPos, BlockState), which is therefore wrong.