Simple: use a loud alarm app that recurs every x minutes until you mark it completed, then resets to the next day.
I use Due, whose loud, persistent ‘Nautical Bellls’ reminder (there are many tones to choose from) never fails to get my attention. In the past I set it up as a weekday alarm that repeated every 2 minutes until acknowledged, whereupon it’d reset for the next weekday morning.Due App — Persistent And Noisy