Mark Hansen wrote:

You do not have to be under an IFR clearance to practice approaches. In
fact, some controllers will say "Practice Approach Approved" rather than
the normal "Cleared for the approach" to make this point clear.


That matches my experience.

You're still VFR while flying IFR practice approaches. No separation or
terrain warning is provided.

My local guys usually say "Cleared for the ILS XX practice approach,
remain VFR".

Real requests for approach usually include the "Are you rated and
equipped?" query if you're not arriving on an IFR plan.