What happens when you navigate to Crave via the On Demand menu of Pik TV? On your Apple TV, open the Pik TV app, navigate to On Demand --> Channels --> Crave. If you can watch here, then it's likely a link problem with Bell. If you can't watch here, then it's TELUS.
It's also worth noting that there are two 'versions' of Crave: Crave ($10) and Crave + Movies + HBO ($20). The $10 version has more limited content, so if you're trying to watch a recent HBO series, you might get a prompt asking for a subscription. There's an overview of Crave packages here: https://www.crave.ca/en/subscribe