We called the call center some days before getting our approval because my husband needs to travel to the US soon, here's what they said: If the PR was approved and he was out of the country we needed to specify that in the email that we'd receive to the create the portal credentials. They couldn't finalize the application for him if he was out of the country so if he was going to leave before we get a response we needed to notify the IRCC. If after getting the approval he needed to travel and the PR card hadn't arrived, he could request a travel document while being out of the country or if we were meeting him out of the country later then we could hand him the PR card, as he needs the TD or the PR card to enter Canada and they could not mail the card outside of the country.
I hope this helps! (our situation: we're on implied status, applied online-outland but came back in the middle of the process and notified them.)