If selected for a random test - at least when crossing the land border you are given a test kit to do via video. Then you have it picked up/dropped off. (…and then wait a week for the result, so pointless) My mom has been “randomly” selected the last two times she’s crossed the border.
I’m going on Ovation at the end of the month …I’ll be filling out ArriveCan twice - for stop in Victoria, then next day to drive home. Once you have your info in the app, it’s pretty straightforward (expect when it crashes your phone and have to reboot - that was fun)