Amazon API Gateway Integrates with AWS Certificate Manager (ACM)

You can now configure custom domains for your APIs on Amazon API Gateway using SSL/TLS certificates provisioned and managed by AWS Certificate Manager (ACM). Now, you can request a certificate from ACM and associate it with your API in minutes using the API Gateway Console, APIs, and CLI/SDKs. Previously, you needed to procure and upload your own SSL certificates to API Gateway in order to configure a custom domain for your APIs.
Quelle: aws.amazon.com