Proper link that Tim Hortons is e-mailing out is is https://www.timhortons.ca/hot-beverage-giveaway
Basically, if you order a hot beverage at Timmies from Oct 28 onward (until 4,780,194 free coffees from this promo have been awarded - projected to be Nov 6), you have a 1 in 9 chance of winning it for free. It's meant to be a resumption of the "Roll Up the Rim to Win" contest that usually happens starting in March of every year (but was terminated early due to COVID-19).
Orders placed through the app are not eligible. So, guess I won't be partaking in this promo!