If you are the account owner or if you have the permissions to manage the account, you can use the app without a card. Simply log in to the app to manage your account and transactions.
If you are not the account owner or do not have account management permissions but would like to use the app, simply request for account management permissions from your account administrator.
If you are a card holder, you can use the app by logging in using the same email address you used when ordering the card. And in this case, you'll need to have the app available to you to be able to authorise some of your online card transactions, track your card payments and add them to your company's expenses.