How to let users know that the updates are not real time

I'm working on a food ordering mobile website. After ordering the meal, the preparation progress screen that aims to give users a rough estimate on what time their meal will be ready. Due to technical limitations, the time estimate won't update automatically. However if users refresh their browser, the time will be updated.

i'm faced with 2 choices

  1. inform the user in words. that they need to refresh their browser
  2. change the words of the time estimate to manage their expectations.

from these which is the better choice. and how should i convey the message, would appreciate examples. Or is there another way to overcome this?

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