Top up your account using PayPal
It is important to point out that having a positive balance (also known as credit, funds, etc) is necessary to be able to send messages. Here you can check how the SMS service is charged.
In summary, even if you are using the free plan, every sent message incurs a cost.
You can top up your account by following these steps:
1. Click on Billing settings
2. Select the amount
3. Fill your billing information.
4. Select PayPal
Click on the blue button, and enter your PayPal username.
5. Finalize the payment
Your corresponding balance will be available, and an invoice will be generated for you to download.
You might be interested in learning how to top up your account by credit card
You might be interested in learning how to top up your account via Wire Transfer