Go in with a positive script.
State the problem, and provide clear examples. Write these down before-hand and keep the descriptions focussed.
Explain the effect on you. For example, you're doing a task, then the supervisor interferes. Breaks your concentration, squashes initiative, wastes time, make you anxious and stressed.
Stress that the supervisor has no problem at all with the quality of your work, nor you with them beyond the micromanaging.
Suggest a solution. For example, could you please tell.the supervisor to back off - perhaps agree what your tasks are to be at the start of your shift, then leave you to it as far as possible. Pitch it as " how can we deal with Micromanager".
But importantly - go in to the meeting with a positive, can-do attittude "got a big of a problem and need your help to fix it" rather than deep moaning and character assassination.of the supervisor.
Good luck! I always hated the micromanaging stop-this-do-that-instead work dynamic.