hello I am integrating microservices via api gateway and i am also using cloudflare for domain mapping i used to generate certificate from the cloudflare and also import the same as ACM certifcate in api gateway and used as custom domain but not having any idea how to implement it completely a little help will be highly appericiated.

Looks like you could use https://www.pulumi.com/docs/reference/pkg/aws/acm/certificate/#importing-an-existing-certificate to import the cert and then i think https://www.pulumi.com/docs/reference/pkg/aws/apigateway/clientcertificate/#look-up To associate it to the gateway. i'm just trying to find relevant methods while following https://aws.amazon.com/about-aws/whats-new/2017/03/amazon-api-gateway-integrates-with-aws-certificate-manager-acm/ so could be very wrong here

in my case its not route53 it is cloudflare