Hello PQ,
Welcome to the community!
If you do not have a Pulse plan, you would have to purchase a Travel pack or use services on a pay-per-use basis.
You should also consider verifying whether your phone is compatible with the local networks. Hong Kong uses different bands/frequencies than North America. You can see the bands/frequencies used by the different countries by selecting from the drop-down menu here (bottom of page). You can also verify the countries bands/frequencies here.
In addition, you might consider verifying that your destinations had good coverage? Mobile phones roam on the existing infrastructure at the destination. Fido's service cannot extend beyond what is available locally. It's the customers' responsibility to check whether their phones would work at their destination. Open Signal can give you an idea of the coverage at your destinations.
Hope this helps 
