On your computer:

1. On your Dashboard, click the Account icon

2. Select Settings

3. Go to Plan & Billing

4. Click Manage under Payment Method

 

 

 

 

5. Enter your card details and click Add Card

On the app:

1. Tap on the ☰ icon at the top left for more options

2. Select Settings

3. Tap on Payment Method

4. Enter the card details and tap Continue