1. Log in to AppExchange:

2. From the user profile menu, click My Installs & Subscriptions.
3. Find the subscription that you want to update.
4. From the dropdown list, select Buy now

Next, follow the steps in the Checkout wizard.
Checkout Step 1: Fill Out your personal details and Billing Information

Checkout Step 2: Choose License and number of users

Checkout Step 3: Payment Method
You can pay via Credit Card or by Bank account. Fill out the required fields for Credit Card or Bank Account.
Checkout Step 4: Finalize payment
Follow the instructions to finalize the Checkout process.