Poparide operates a service under carpooling regulations which helps recover costs when you're already driving from A to B. In most Canadian provinces, this is not considered a commercial activity and therefore is not taxable. Check here for the regulations in your province.
However, if you are already claiming your driving costs as a business expense with the CRA, you could be "double-dipping", and we recommend checking with your accountant on how to declare your Poparide contributions.
Please note that carpooling is different from the CRA's definition of "ridesharing", which regulates for-profit ride-hailing services like Uber and Lyft. For these ride-hailing services, you are required to collect GST/HST and declare your income, as they are considered to be commercial activity.