You can use your Juno Debit Card anywhere outside of the USA as long as you have Foreign Transactions turned on in your Card Settings. To enable Foreign transactions, please follow these steps:
Go to your Juno Dashboard.
Under the Card tab, select Manage Card option.
Toggle on the Foreign Transactions button.
Voila! You can make foreign transactions without any issues.
Please note Juno does not charge a fee for foreign transactions.