Creating vanilla Proton environment fails due to insufficient CodeBuild concurrent build quota

I'm creating a basic AWS Proton setup using CDK and following the steps in this article: https://aws.amazon.com/blogs/containers/announcing-aws-cdk-support-and-codebuild-provisioning-for-aws-proton.

I have successfully created a Proton environment template that syncs with Git. The template defines an empty environment.

However, when I create an environment from that template, it fails due to the error below:

This account lacks sufficient CodeBuild concurrent build quota. CodeBuild Provisioning requires at least 5 and this account current has 1. To correct this, request a limit increase in Service Quotas. Service code: codebuild Quota code: L-9D07B6EF

I requested a limit increase and it was denied.