What happens if you apply for an eTA when you already have one?

[MatthewBridge]

I bought an eTA about three years ago.
I know they don't expire until after five years but I'd like to be sure of having a valid eTA and am unable to check if my current eTA is valid as I don't have the relevant email containing the eTA number.

I assume that buying one now would either give me another five years of eTA or I would hear that my eTA has been invalidated and that I therefore cannot be issued a new one.
Would this be the case?

 

[LuisRosales213]

I have done the same and need to travel tomorrow. Did you end up finding out?

 

[LuisRosales213]

I have been searching everywhere online and no one but you seems to have the question and no replies