https://www.slab.org.uk/faqs/do-i-still-need-to-be-on-the-police-station-duty-plan-to-claim-for-advice-and-assistance-given-to-my-own-clients/
You do not have to be on the police station duty plans to advise/attend and submit an account.
If you are not on the Duty plans you will not get any calls for a duty attendance/advice, but will still get calls from the police if your client has named you as their solicitor.