Flying to Canada: will we need to show evidence of ETA?

[Mykingdomforanickname]

We are due to go on a holiday to Canada and have obtained ETAs. Will we need to quote a reference number/show the e-mail etc at check-in? Or do we not need to produce anything at check-in in relation to the ETA because check-in staff will enter our passport numbers and check on their system that ETAs have been obtained? TIA

It will all be automated but I always take a copy just in case. I've never needed it though.

Thank you.