First, make sure you've run npm i -g serverless and added your AWS credentials.
Deploying for the first time can take 10-20 minutes since it needs to create the ElasticSearch instance. If there is an error, you may get ROLLBACK_IN_PROGRESS the next time you try to deploy. Give it a few minutes and then try again.
Once deployed, navigate to the returned endpoint url and you'll see the graphql playground, where you can run the following queries:
mutation{
addTodo(id:"123",title:"Get Milk")
}
query{
getById(id:"123"){
id
todos{
title
completed
}
}
}
The AWS Free Tier covers most of these services, but running an ElasticSearch instance on AWS can be expensive. Make sure to run serverless remove once you're done.