Unable to get the GFCI plug to reset why
If you know the manufacturer of the GFCI you could probably look up to see what a flashing red light means, but I'm guessing it indicates a miswired GFCI or some other kind of internal failure.

If you just installed the GFCI, double-check that the wiring has been done properly (i.e. you did not swap the LINE and LOAD sides, swap hot &amp; neutral, etc).

If it is an old GFCI, maybe it is just time to replace it. They can fail over time, especially older models were more prone to failure.