Follow these steps to add a new app to your Teams account:

1. Step 1: Sign in to your Teams account
2. Step 2: Select the app from the store and click on Add
3. Step 3: Confirm you want to add the app to your Teams by hitting the Accept button
4. Step 4: Once the app is added, it will appear on the left-hand side of the Teams screen
5. Step 5: You can now start using the app