Reporting to someone works even when the someone offers no advice. Knowing that the size breach will have to be said out loud on Friday tends to prevent the size breach on Tuesday.
It works only with specifics. Vague check-ins about how it is going produce nothing. Share the numbers that matter - rule adherence, largest loss, unplanned trades - and agree that both of you name the uncomfortable ones.
Choose someone with no financial stake in your activity. A partner who earns from your subscription, your volume, or your referrals is not an accountability partner. See coach-vs-therapist for where paid help fits.
Related: peer-review-group, trading-coach, coach-vs-therapist, behaviour-journal