You don't pay for an aws account. But you need to give your credit card information in case that you consume more.
With the first year there is a free tier and even afterwards you don't need to pay for the lambda function calls if you just use it personally.
You can also get promotional credits: for funding https://developer.amazon.com/en-US/alexa/alexa-skills-kit/new/aws-promotional-credits.
Additionally you can create some alerts for spending.
You don't pay for an aws account. But you need to give your credit card information in case that you consume more. With the first year there is a free tier and even afterwards you don't need to pay for the lambda function calls if you just use it personally. You can also get promotional credits: for funding https://developer.amazon.com/en-US/alexa/alexa-skills-kit/new/aws-promotional-credits. Additionally you can create some alerts for spending.