I get a red lighting bolt an the time but can’t open my watch

If your watch requires charging, a red lightning bolt  appears on the screen. (You might need to press the side button to make the watch face appear.) When your watch is charging, the red lightning bolt  changes to a green or yellow lightning bolt . If your screen is blank or the charging cable icon and a red lightning bolt  appear on the screen, charge your watch for up to 30 minutes. 

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What to do: If your Apple Watch won't charge or it won't turn on - Apple Support