Hi, my name is Nnamdi, and I am a Solutions Architect on AWS. I am experienced in deploying full architectures on AWS and I can work with you on this project.
I understand you want to deploy your API to a web-facing interface on which users can create an account, get authorized, and are billed for each time they use it. To make it work:
First, to deploy your API, you need an API gateway which will allow your application to interact directly with your user.
Secondly, what volume of traffic or requests do you expect for your application? We may need to optimize your compute layer using AWS Autoscaling and an ALB. If you have a global audience, then we should use a CloudFront distribution.
Thirdly, will you be managing your users locally or you want AWS to manage it. For the latter, I will suggest AWS Identity Center for automated user authentication and management. For local management, I will suggest using Amazon Cognito to authenticate users with SAML 2.0 and link it with Amazon EventBridge.
Lastly to be able to monetize each user request, we need to call a Lambda function after authorization, to call your payment gateway. How do you want to implement payment collection? Do you already have that integration in your application?
I will be glad to work with you on every aspect of the project. Feel free to provide as much information as I will need to provide an optimal solution for your environment.
I look forward to hearing back from you.